Submersible vehicle, control system, and control method

Abstract

The purpose is to prevent the propulsion system of a submersible from becoming entangled with objects. [Solution] The submersible body 1 according to this embodiment includes a plurality of propulsion units 12 that generate a thrust force to propel the submersible body as it submerges underwater, an object detection unit 162 that detects an object to be detected, and a propulsion control unit 163 that controls the target propulsion unit 12 that has an object to be detected within a first distance when the object detection unit 162 detects that an object to be detected is within a first distance from any of the plurality of propulsion units 12, so that the object to be detected does not approach the plurality of propulsion units 12.

Description

Technical Field

[0001] The present invention relates to an underwater vehicle, a control system, and a control method that can suppress the entrainment of an object.

Background Art

[0002] A seabed exploration system using an underwater drone connected to a buoy by a rope is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An underwater vehicle that submerges in water has a propulsion unit (e.g., a thruster) that generates a propulsion force to propel itself. The propulsion unit may entrain an object present in the water and cause damage to the underwater vehicle.

[0005] Therefore, the present invention has been made in view of these points, and an object thereof is to suppress the propulsion unit of the underwater vehicle from entraining an object.

Means for Solving the Problems

[0006] An underwater vehicle according to a first aspect of the present invention includes a plurality of propulsion units that generate a propulsion force to propel the underwater vehicle that submerges in water, an object detection unit that detects a detection target object, and a propulsion control unit that controls a target propulsion unit that is the propulsion unit within a first distance where the object detection unit has detected that the detection target object is within the first distance from any one of the plurality of propulsion units, so that the detection target object does not approach the plurality of propulsion units.

[0007] The propulsion control unit may control the target propulsion unit so as not to generate the propulsion force.

[0008] The propulsion control unit may control the target propulsion unit to generate a propulsion force that propels the submersible in a direction different from the propulsion direction that was propelling the submersible at the time the object detection unit detected the target object.

[0009] The propulsion control unit may, after controlling the target propulsion unit while the submersible is being propelled in the direction that propelled the submersible at the time the object detection unit detected the target object, control the target propulsion unit to generate the propulsion force that propels the submersible after a predetermined time has elapsed from the time when the object detection unit no longer detects that the target object is within the first distance from any of the multiple propulsion units.

[0010] The propulsion control unit may, after controlling the target propulsion unit while the submersible is being propelled in the direction that propelled the submersible at the time the object detection unit detected the target object, control the target propulsion unit to generate the propulsion force to propel the submersible if the detected object is separated from any of the multiple propulsion units by a third distance or more greater than the first distance.

[0011] The propulsion control unit may control the target propulsion unit so that the detected object does not approach the multiple propulsion units if at least one of the type, shape, or volume of the detected object detected by the object detection unit to be within the first distance from any of the multiple propulsion units meets a predetermined criterion.

[0012] The propulsion control unit may control the target propulsion unit so that the detected object does not approach any of the propulsion units if the detected object detected by the object detection unit is within the first distance associated with the detected object in a distance management table in which objects and the first distance are associated, from any of the multiple propulsion units.

[0013] The object detection unit may detect that the object to be detected is within the first distance from any of the multiple propulsion units, based on detection data output from multiple object detection sensors corresponding to each of the multiple propulsion units.

[0014] The object detection unit may, based on the shape of the object indicated by the detection data, detect a cable connecting an underwater submersible and an external device on a surface-navigating vehicle present on the water surface as the object to be detected.

[0015] The object detection sensor may be a magnetic sensor that detects the strength of a magnetic field, and the object detection unit may detect a cable carrying an electric current connecting an underwater submersible and an external device on a surface-navigating body present on the water surface as the object to be detected, based on the strength of the magnetic field detected by the magnetic sensor.

[0016] The submersible may further include a current meter for measuring the direction and velocity of water flow, and a distance determination unit for determining the first distance based on the direction and velocity of water flow measured by the current meter.

[0017] The distance determination unit may determine the first distance such that the value of the first distance when the direction of water flow is in the direction from the position of the object to be detected to the position of the underwater submersible is greater than the value of the first distance when the direction of water flow is in the direction from the position of the underwater submersible to the position of the object to be detected.

[0018] The distance determination unit may determine the first distance such that, when the direction of the water flow is from the position of the object to be detected to the position of the underwater submersible, the greater the water flow velocity, the greater the value of the first distance.

[0019] The propulsion control unit may, when the object detection unit detects that the object to be detected is within the first distance from any of the multiple propulsion units, control the target propulsion unit so that the object to be detected does not approach within a second distance, which is less than or equal to the first distance, from the multiple propulsion units.

[0020] A control system according to a second aspect of the present invention comprises an underwater submersible that moves underwater and an external device capable of communicating with the underwater submersible, wherein the underwater submersible has a plurality of propulsion units that generate a propulsion force to propel the underwater submersible, an object detection unit that detects an object to be detected, an underwater communication unit that transmits object information indicating the object to be detected that is within a first distance from any of the plurality of propulsion units to the external device and receives a control signal for controlling the target propulsion unit which is the propulsion unit in which the object to be detected is within the first distance, and a propulsion control unit that controls the target propulsion unit in accordance with the received control signal so that the object to be detected does not approach the plurality of propulsion units, wherein the external device has a signal generation unit that generates the control signal and a device communication unit that receives the object information from the underwater submersible and transmits the generated control signal to the underwater submersible.

[0021] A control method according to a third aspect of the present invention is a method executed by a processor that controls an underwater submersible having a plurality of propulsion units that generate a thrust force to propel an underwater submersible that is submersible underwater, and comprises the steps of: detecting a target object; and, when it is detected that the target object is within a first distance from any of the plurality of propulsion units, controlling the target propulsion unit that is the propulsion unit in which the target object is within the first distance, so as to prevent the target object from approaching the plurality of propulsion units. [Effects of the Invention]

[0022] According to the present invention, there is an effect that the propulsion unit of the underwater vehicle can be suppressed from entraining an object.

Brief Description of the Drawings

[0023] [Figure 1] It is a diagram showing an outline of the operation of the control system S. [Figure 2] It is a diagram showing an installation example of the sensor 13. [Figure 3] It is a diagram showing an example of the configuration of the underwater vehicle 1. [Figure 4] It is a diagram showing an example of a distance management table for each propulsion unit. [Figure 5] It is a diagram showing an example of a distance management table for each object. [Figure 6] It is a diagram showing an example of the configuration of the external device 2. [Figure 7] It is a flowchart showing the flow of the process according to the present embodiment. [Figure 8] It is a diagram showing an example of another configuration of the underwater vehicle 1.

Modes for Carrying Out the Invention

[0024] <First Embodiment> [Outline of the Control System S] FIG. 1 is a diagram showing an outline of the operation of the control system S. The control system S includes an underwater vehicle 1, an external device 2, and a ship 3. The control system S is a system for suppressing the underwater vehicle 1 from entraining an object existing in the water.

[0025] The submersible vehicle 1 is a submersible vehicle capable of operating underwater, such as an underwater drone or a water-air combined drone. The submersible vehicle 1 has a plurality of propulsion units 12 that generate thrust to propel the submersible vehicle 1. As the plurality of propulsion units 12, the submersible vehicle 1 has, for example, three thrusters on each of its left and right sides (i.e., a total of six thrusters). In Figure 1(a), which shows a side view of the submersible vehicle 1, three thrusters can be seen, and in Figure 1(b), which shows a bottom view of the submersible vehicle 1, all six thrusters can be seen.

[0026] External device 2 is a device that controls the submersible 1. External device 2 is, for example, a controller that transmits control signals to control the multiple propulsion units 12 of the submersible 1. The submersible 1 and external device 2 are connected by a cable C for transmitting and receiving control signals. This allows the pilot P on board the ship 3 to control the movement of the submersible 1 by operating external device 2.

[0027] Alternatively, instead of the external device 2, a USV (unmanned surface vehicle) may be connected to the submersible 1 by cable C. In this case, a pilot P located on land or elsewhere operates the external device 2, and the USV receives the control signals transmitted by the external device 2. The USV then controls the movement of the submersible 1 by transmitting the received control signals to the submersible 1 via cable C. In other words, the USV functions as a relay device for control signals.

[0028] Incidentally, in order to enable the agile movement of the underwater submersible 1 and to reduce the burden on cable C caused by the cable being taut, it is preferable to keep cable C slack while the underwater submersible 1 is submerged. However, when cable C is slack, the propulsion unit 12 of the underwater submersible 1 may entangle cable C, causing damage to the underwater submersible 1. In addition, the propulsion unit 12 of the underwater submersible 1 may entangle organisms or objects such as debris present in the water.

[0029] To solve this problem, one method is for the pilot P of the underwater submersible 1, who is aboard the ship 3, to monitor the images captured by a camera installed on the underwater submersible 1 and, if an object is present near the propulsion unit 12, to control the propulsion unit 12 to prevent the object from approaching the propulsion unit 12 any further. However, this method has the problem of placing a heavy burden on pilot P, which interferes with the pilot P's duties that he is supposed to be performing.

[0030] Therefore, in this embodiment, each of the multiple propulsion units 12 is provided with a sensor 13 for detecting the proximity or contact of an object. Figure 2 is a diagram showing an example of the installation of the sensors 13, and is a bottom view of the thruster. In the example shown in Figure 2, three sensors 13 are provided for one thruster near the water intake surface of the cylinder constituting the thruster and along the outer circumference of the cylinder. As a result, the submersible 1 can detect the presence of a target object based on the detection data output from the sensors 13.

[0031] When the submersible 1 detects that a target object is within a predetermined distance from any of its multiple propulsion units 12, it controls the propulsion unit 12 that has the target object within the predetermined distance so that the target object does not approach the propulsion unit 12. For example, the submersible 1 stops or reverses the rotation of the thruster that has the target object within the predetermined distance for a certain period of time. Reverse rotation is, for example, a rotation that generates a water flow in the direction in which the target object is located when viewed from the thruster.

[0032] This prevents the object to be detected, which was located near the propulsion unit 12 of the submersible 1, from approaching the propulsion unit 12, thereby suppressing the propulsion unit 12 from becoming entangled with the object. If it is confirmed that the object has moved further away from the propulsion unit 12 than a predetermined distance, the submersible 1 may control the propulsion unit 12 as it was controlled before detecting the object. For example, the submersible 1 rotates its thrusters in the forward direction. Forward rotation is, for example, a rotation that generates a water flow in the direction of the thrusters when viewed from the location where the object to be detected was located.

[0033] In this way, when the submersible 1 detects that a target object is near any of its multiple propulsion units 12, it can control the propulsion unit 12 that is near the target object so that the target object does not approach the propulsion unit 12. This reduces the burden on the pilot P and prevents damage to the submersible 1 caused by the propulsion unit 12 becoming entangled with the object.

[0034] [Configuration and operation of submersible vehicle 1] Figure 3 shows an example of the configuration of the underwater submersible 1. The underwater submersible 1 comprises a submersible communication unit 11, a plurality of propulsion units 12, sensors 13, a current meter 14, a memory unit 15, and a control unit 16. The control unit 16 has a distance determination unit 161, an object detection unit 162, and a propulsion control unit 163. In Figure 2, for the sake of simplicity, one sensor 13 is shown for each propulsion unit 12, but it is preferable to provide three or more sensors 13 for each propulsion unit 12 in order to improve the accuracy of object detection.

[0035] The submersible communication unit 11 is a communication interface for communicating with an external device 2 located on the surface of the water via cable C. The submersible communication unit 11 receives control signals for controlling the propulsion unit 12 input to the external device 2 by the pilot P, and inputs the received control signals to the propulsion control unit 163. The submersible communication unit 11 also transmits information indicating the attitude, direction of travel, and course of the underwater submersible 1 to the external device 2. In addition, the submersible communication unit 11 transmits image data indicating the detected object detected by the underwater submersible to the external device 2.

[0036] The propulsion unit 12 is a physical configuration that generates thrust to propel the underwater submersible 1. The propulsion unit 12 includes, for example, a thruster, a motor for rotating the thruster, and an electronic speed controller (ESC) that adjusts the rotational speed and direction of the motor according to control signals input from the propulsion control unit 163. The propulsion unit 12 may generate thrust so that the underwater submersible 1 remains in a fixed position underwater, a so-called hovering state.

[0037] Sensor 13 is an object detection sensor that detects objects present in the water. Sensor 13 can be, for example, a magnetic sensor, an acoustic sensor, an optical sensor, a camera, or a contact detection sensor. Sensor 13 inputs detection data indicating the detected object to the object detection unit 162. The object detection process using each sensor is described below.

[0038] A magnetic sensor is a sensor that detects the strength of a magnetic field. For example, a magnetic sensor detects the strength of the magnetic field around cable C, which is formed by the electric current flowing through cable C. The data detected by the magnetic sensor is, for example, data indicating the distance from sensor 13 to cable C.

[0039] A sound wave sensor is a sensor that emits sound waves and receives reflected waves formed when those sound waves are reflected by an object, thereby acquiring information about the object. An example of this is an acoustic sonar. The detection data of the sound wave sensor is, for example, data indicating the distance from the sensor 13 to the object, or the volume, shape, or material of the object.

[0040] A light sensor is a sensor that acquires information about an object by emitting laser light and receiving the reflected light formed when that laser light is reflected by the object. An example of this is LiDAR (Light Detection and Ranging). The detection data of the light sensor is, for example, data indicating the distance from the sensor 13 to the object, or the volume, shape, or material of the object.

[0041] The camera captures images of the area around the propulsion unit 12. In deep water, or even at night in shallow water, the cable C may be difficult to distinguish in the images captured by the camera. Therefore, by using a cable C coated with luminous paint or fluorescent paint, the cable C becomes easier to distinguish in the images captured by the camera.

[0042] The contact detection sensor is a sensor that converts the pressure or vibration applied by an object to the sensor 13 into an electrical signal. The contact detection sensor is, for example, a sheet-shaped sensor that can be incorporated into or attached to the propulsion unit 12. The detection data of the contact detection sensor is data indicating the magnitude of the pressure or vibration applied to the sensor 13.

[0043] The flow meter 14 is a measuring instrument that measures the direction and velocity of water flow. The flow meter 14 is, for example, an ultrasonic Doppler flow meter. The flow meter 14 inputs the measured data indicating the direction and velocity of the water flow to the distance determination unit 161.

[0044] The storage unit 15 is a storage medium including ROM (Read Only Memory) and RAM (Random Access Memory). The storage unit 15 stores the program executed by the control unit 16. The storage unit 15 stores information processing programs that cause the control unit 16 to function as, for example, a distance determination unit 161, an object detection unit 162, and a propulsion control unit 163. The storage unit 15 stores distance management tables for each propulsion unit and distance management tables for each object.

[0045] Figure 4 shows an example of a distance management table for each propulsion unit. In the distance management table for each propulsion unit, propulsion unit identification information, a first distance, and a second distance are associated. The propulsion unit identification information is information for identifying the propulsion unit 12, such as the ID of each propulsion unit 12. The first distance is the distance between the object to be detected and the propulsion unit 12, which serves as a standard for controlling the propulsion units 12 so that the object to be detected does not approach any of the propulsion units 12. The second distance is the distance that prevents the object to be detected from approaching any of the propulsion units 12. The second distance is, for example, a distance less than or equal to the first distance, but it may also be the same distance as the first distance.

[0046] The first and second distances may be set to different values ​​for each of the multiple propulsion units 12, a common value may be set for some of the propulsion units 12, or a common value may be set for all of the propulsion units 12. Furthermore, the method of setting the values ​​for the first and second distances may differ; for example, a different first distance may be set for each of the multiple propulsion units 12, and a common second distance may be set for all of the propulsion units 12. Also, the appropriate values ​​for the first and second distances may differ depending on the direction or velocity of the water flow, so the values ​​for the first and second distances do not have to be fixed values.

[0047] Figure 5 shows an example of a distance management table for each object. In the distance management table for each object, the type of object to be detected, the volume of the object, whether or not the propulsion unit 12 is controlled, the first distance, and the second distance are associated. The type of object to be detected is the type of underwater object detected by the object detection unit 162, which will be described later (cable C, underwater debris, or underwater organisms, etc.). Whether or not the propulsion unit 12 is controlled indicates whether or not the propulsion unit 12 is controlled to prevent the detected object from approaching the propulsion unit 12.

[0048] If the object to be detected is cable C, the first and second distances are set. On the other hand, if the object to be detected is underwater debris, medium-sized debris (e.g., 10 cm) is set. 3 ~13cm 3 (less than 13cm) and larger pieces of trash (e.g., 13cm) 3 The probability of the propulsion unit 12 engulfing the above-mentioned debris is not high. For this reason, the first and second distances are not set for medium-sized and large debris (i.e., the propulsion unit 12 is not controlled to prevent the detected object from approaching the propulsion unit 12). If the type of detected object is an aquatic organism, it is possible that the aquatic organism may approach the submersible 1 on its own, so medium-sized organisms (for example, 10 cm) are not targeted. 3 ~13cm 3 A first distance and a second distance are also set for aquatic organisms (less than 100 cm).

[0049] The control unit 16 is, for example, a CPU (Central Processing Unit). The control unit 16 functions as a distance determination unit 161, an object detection unit 162, and a propulsion control unit 163 by executing information processing programs stored in the memory unit 15.

[0050] The distance determination unit 161 determines the first and second distances associated with each of the multiple propulsion units 12 by referring to the distance management table for each propulsion unit shown in Figure 4. Alternatively, the distance determination unit 161 may determine the first and second distances associated with at least one of the type or volume of the detected object detected by the object detection unit 162, which will be described later, by referring to the distance management table for each object shown in Figure 5.

[0051] The distance determination unit 161 inputs information indicating the first distance determined for each of the multiple propulsion units 12 to the object detection unit 162, and inputs information indicating the second distance determined for each of the multiple propulsion units 12 to the propulsion control unit 163.

[0052] The distance determination unit 161 may determine the first distance based on the water flow direction and velocity measured by the flow meter 14. For example, the distance determination unit 161 determines the first distance as a value calculated by substituting the water flow direction and velocity indicated by the measurement data input from the flow meter 14 into a predetermined calculation formula. For example, the distance determination unit 161 may determine the first distance as a distance obtained by multiplying the first distance in the distance management table shown in Figure 4 by a coefficient determined according to the water flow velocity (m / s). The distance determination unit 161 may determine the second distance based on the water flow direction and velocity measured by the flow meter 14.

[0053] Incidentally, when the water flow direction is a first direction, where water flows from the position of the object to be detected to the position of the submersible 1, the propulsion unit 12 is more likely to entangle the object to be detected compared to when the water flow direction is a second direction, where water flows from the position of the submersible 1 to the position of the object to be detected. For this reason, the distance determination unit 161 determines the first distance such that the value of the first distance when the water flow direction is the first direction is larger than the value of the first distance when the water flow direction is the second direction. For example, the distance determination unit 161 determines a larger value as the first distance for thrusters whose water intake direction (for example, the direction perpendicular to the water intake surface of the thruster) is closer to the water flow direction. The distance determination unit 161 may determine the second distance in a similar manner.

[0054] Furthermore, if the water flow direction is a first direction, where water flows from the position of the object to be detected towards the position of the submersible 1, the greater the water flow velocity, the more likely the propulsion unit 12 is to entangle the object to be detected. For this reason, the distance determination unit 161 determines the first distance such that, when the water flow direction is a first direction, the greater the water flow velocity, the greater the first distance. For example, for multiple thrusters in the water intake direction whose difference from the water flow direction is within a predetermined threshold, the distance determination unit 161 determines the first distance such that the greater the water flow velocity, the greater the first distance. The distance determination unit 161 may determine the second distance in a similar manner.

[0055] In cases where the water flow direction or velocity of the propulsion unit 12 is such that it is likely to entangle the object to be detected, setting the first and second distances to relatively large values ​​makes it possible to move the object to be detected away from the propulsion unit 12 earlier. Conversely, if the water flow direction or velocity of the propulsion unit 12 is such that it is unlikely to entangle the object to be detected, the object to be detected may move away from the propulsion unit 12 even without control of the propulsion unit 12 to prevent the object from approaching the propulsion unit 12. In this case, setting the first and second distances to relatively small values ​​eliminates the need to perform such control of the propulsion unit 12 unnecessarily early. As a result, the operation of the propulsion unit 12 becomes stable, and the diving time and diving route of the underwater submersible 1 become stable.

[0056] The object detection unit 162 detects the object to be detected. For example, based on detection data indicating the results detected by the sensor 13, the object detection unit 162 detects the distance from the sensor 13 to the object to be detected, or the volume, shape, or material of the object to be detected.

[0057] The object detection unit 162 may detect the presence of a target object within a first distance from any of the multiple propulsion units 12 based on detection data output from multiple sensors 13 corresponding to each of the multiple propulsion units 12. Specifically, the object detection unit 162 identifies the propulsion unit 12 in which the target object is located within a first distance based on the strength of the magnetic field, the strength of the reflected sound waves, the strength of the reflected light, the magnitude of the fluorescence intensity in the image, or the magnitude of the pressure or vibration applied to the sensor 13, as indicated by the detection data. The object detection unit 162 inputs information indicating the identified propulsion unit 12 to the propulsion control unit 163.

[0058] The object detection unit 162 may detect the cable C connecting the submersible 1 and the external device 2 on the ship 3, which is a surface-navigating object, as the object to be detected, based on the shape of the object indicated by the detection data. Specifically, the object detection unit 162 may detect the cable C as the object to be detected by comparing the reflected sound waves, reflected light, or fluorescence distribution in the image indicated by the detection data with the reflected sound waves, reflected light, or fluorescence distribution in the image that indicate the shape of the cable C stored in the memory unit 15.

[0059] The object detection unit 162 may detect a cable C carrying an electric current as a target object, based on the strength of the magnetic field detected by the magnetic sensor, connecting the underwater submersible 1 and the external device 2 on the ship 3, which is a surface-navigating object on the water surface. Specifically, the object detection unit 162 may detect the cable C as a target object when the strength of the magnetic field indicated by the detection data is above a threshold.

[0060] When the object detection unit 162 detects that a target object is within a first distance from any of the multiple propulsion units 12, the propulsion control unit 163 controls the target propulsion unit 12 that has the target object within the first distance so that the target object does not approach any of the multiple propulsion units 12. For example, when the object detection unit 162 inputs information indicating the target propulsion unit 12 in which the target object is within the first distance identified by the object detection unit 162, the propulsion control unit 163 controls the target propulsion unit 12 so that the target object does not approach any of the multiple propulsion units 12.

[0061] The propulsion control unit 163 may, when the object detection unit 162 detects that a target object is within a first distance from any of the multiple propulsion units 12, control the target propulsion unit 12 so that the detected object does not approach within a second distance, which is less than or equal to the first distance, relative to the multiple propulsion units 12. For example, when the object detection unit 162 inputs information indicating a target propulsion unit 12 in which a target object is located within the first distance identified by the object detection unit 162, the propulsion control unit 163 may control the target propulsion unit 12 so that the detected object does not approach within a second distance from any of the multiple propulsion units 12.

[0062] The propulsion control unit 163 may control the target propulsion unit 12 so as not to generate thrust to propel the submersible 1 when the object detection unit 162 detects that a target object is within a first distance from any of the multiple propulsion units 12. For example, the propulsion control unit 163 may stop the rotation of the thruster if a target object is within the first distance for a certain period of time (for example, several seconds to tens of seconds). By controlling the target propulsion unit 12 so as not to generate thrust, the propulsion control unit 163 can suppress the propulsion unit 12 from entangling an object in the water.

[0063] The propulsion control unit 163 may, when the object detection unit 162 detects that a target object is within a first distance from any of the multiple propulsion units 12, control the target propulsion unit 12 to generate a thrust force that propels the submersible 1 in a direction different from the propulsion direction that was propelling the submersible 1 at the time the object detection unit 162 detected the target object. The propulsion control unit 163 may, for example, reverse the rotation of the thruster that has a target object within the first distance for a certain period of time (for example, 1 second to several seconds).

[0064] The propulsion control unit 163 controls the target propulsion unit 12 to generate a thrust force that propels the submersible 1 in a direction different from the propulsion direction. This creates a water flow opposite to the direction that would draw an object underwater towards the propulsion unit 12, causing the object to move away from the propulsion unit 12. As a result, the propulsion unit 12 can more effectively prevent the object from becoming entangled with the object underwater. Furthermore, even if the propulsion unit 12 does become entangled with an object underwater, the propulsion control unit 163 can create a water flow in the opposite direction, potentially untangling the object from the propulsion unit 12.

[0065] The propulsion control unit 163 may control the thrusters according to either a stop setting, which stops the thrusters when a target object approaches them, or a reverse rotation setting, which reverses the rotation of the thrusters. In the case of the stop setting, if the object detection unit 162 detects that a target object is within a first distance from any of the thrusters, the propulsion control unit 163 stops the rotation of the thruster to which the target object is within the first distance for a certain period of time.

[0066] In the reverse rotation setting, if the object detection unit 162 detects that the object to be detected is within a first distance (e.g., 10m) of any of the thrusters, the propulsion control unit 163 reverses the thruster on which the object to be detected is within the first distance at a low speed. Even if the thruster is reversed at a low speed, if the object detection unit 162 detects that the object to be detected is within a second distance (e.g., 5m) less than or equal to the first distance of any of the thrusters, the propulsion control unit 163 reverses the thruster on which the object to be detected is within the second distance at a high speed. Then, if the object to be detected is now more than the second distance away from any of the thrusters due to the high-speed reverse rotation, the propulsion control unit 163 may return the thruster's reverse rotation to a low speed, and further, if the object to be detected is now more than the first distance away from any of the thrusters due to the low-speed reverse rotation, the propulsion control unit 163 may stop the thruster's reverse rotation.

[0067] However, as mentioned above, depending on the type and volume of the object to be detected, the probability of the object being caught by the propulsion unit 12 may not be high. Therefore, the propulsion control unit 163 may control the target propulsion unit 12 so that the object being detected does not approach the multiple propulsion units 12 if at least one of the type, shape, or volume of the object to be detected by the object detection unit 162, which is within a first distance from any of the multiple propulsion units 12, meets a predetermined criterion.

[0068] For example, if the object detection unit 162 detects that the detected object is cable C within a first distance from any of the multiple propulsion units 12, the propulsion control unit 163 controls the target propulsion unit 12 so that the detected object does not approach the multiple propulsion units 12. There are also cases where the object detection unit 162 detects that the detected object is an object other than cable C within a first distance from any of the multiple propulsion units 12. In this case, for example, if the detected object other than cable C is less than a predetermined volume or has a predetermined shape (e.g., spherical or elliptical), the propulsion control unit 163 may control the target propulsion unit 12 so that the detected object does not approach the multiple propulsion units 12.

[0069] Thus, if the detected object is not likely to be caught in the propulsion unit 12, the propulsion control unit 163 does not control the target propulsion unit 12 to prevent the detected object from approaching the propulsion unit 12. This makes it less likely for the submersible body 1 to stop or move in a direction different from the intended one due to unnecessary control. As a result, the submersible body 1's diving time and diving route become more stable.

[0070] Assume that after the object detection unit 162 detects the target object and the submersible 1 is propelled in the same direction, the target propulsion unit 12 is controlled, and then the object detection unit 162 no longer detects the target object within a first distance from any of the propulsion units 12. In other words, assume that the propulsion control unit 163 controls the target propulsion unit 12 to prevent the target object from approaching the propulsion unit 12, so that the target object moves at least a first distance away from any of the propulsion units 12. In this case, the propulsion control unit 163 may control the target propulsion unit 12 to generate thrust to propel the submersible 1 after a predetermined time has elapsed from the point at which detection ceases.

[0071] Specifically, the object detection unit 162 detects a target object, causing the propulsion control unit 163 to stop or reverse the thruster for a certain period of time. After this, the object detection unit 162 no longer detects that the target object is within a first distance from any of the thrusters. In this case, the propulsion control unit 163 may restart the thruster rotation after a predetermined time has elapsed from the point at which detection ceases.

[0072] In this way, when a detected object that has approached the propulsion unit 12 moves away from the propulsion unit 12, the propulsion control unit 163 controls the target propulsion unit 12 to generate thrust again to propel the submersible body 1, allowing the submersible body 1 to quickly resume diving in the planned direction. As a result, the diving time and diving route of the submersible body 1 are stabilized.

[0073] The propulsion control unit 163 may also control the target propulsion unit 12 to generate thrust to propel the submersible 1 when the detected object is located at a distance greater than the first distance (a third distance or more) from any of the multiple propulsion units 12. For example, the propulsion control unit 163 may stop or reverse the rotation of a thruster for a certain period of time, and then restart the rotation of the thruster when the detected object is located at a distance greater than the third distance from any of the multiple thrusters. The propulsion control unit 163 may restart the rotation of the thruster immediately as soon as the detected object is located at a distance greater than the third distance from any of the multiple thrusters, or it may restart the rotation of the thruster after a predetermined time has elapsed after the detected object is located at a distance greater than the third distance from any of the multiple thrusters.

[0074] In this way, it is possible to prevent the detected object from approaching within the first distance from the propulsion unit 12 immediately after controlling the target propulsion unit 12 to generate thrust again to propel the submersible body 1. As a result, the method of controlling the propulsion unit 12 is not frequently changed (for example, switching between stopping and restarting), so the submersible body 1's diving time and diving route are stabilized. The third distance may also be determined by the distance determination unit 161 based on the water flow direction and velocity measured by the current meter 14.

[0075] [Configuration and operation of external device 2] Figure 6 shows an example of the configuration of the external device 2. The external device 2 comprises a device communication unit 21, a display unit 22, an operation unit 23, a storage unit 24, and a control unit 25. The control unit 25 has a display processing unit 251 and a signal generation unit 252.

[0076] The device communication unit 21 is a communication interface for communicating with the submersible 1 via cable C. The device communication unit 21 receives information from the submersible 1 indicating its attitude, direction of travel, and course, and inputs the received information to the display processing unit 251. The device communication unit 21 also receives image data from the submersible 1 indicating the detected object detected by the submersible 1, and inputs the received image data to the display processing unit 251. Furthermore, the device communication unit 21 transmits control signals to the submersible 1 for controlling the propulsion unit 12 of the submersible 1, which are input from the signal generation unit 252.

[0077] The display unit 22 is a display for displaying information. The operation unit 23 is a device that receives input from the pilot P of the submersible 1, and is, for example, a touch panel. When the operation unit 23 receives an operation from the pilot P to generate a control signal for controlling the propulsion unit 12 of the submersible 1, for example, it inputs the instruction to generate the control signal to the signal generation unit 252.

[0078] The memory unit 24 is a storage medium including ROM and RAM. The memory unit 24 stores the program that the control unit 25 executes. The memory unit 24 stores an information processing program that causes the control unit 25 to function, for example, as a display processing unit 251 and a signal generation unit 252.

[0079] The control unit 25 is, for example, a CPU. The control unit 25 functions as a display processing unit 251 and a signal generation unit 252 by executing an information processing program stored in the memory unit 24.

[0080] The display processing unit 251 displays information on the display unit 22 indicating the attitude, direction of travel, and course of the submersible 1. The display processing unit 251 also displays an image on the display unit 22 indicating the detected object detected by the submersible.

[0081] Furthermore, if the propulsion unit 12 is controlled to prevent the detected object from approaching the propulsion unit 12 of the submersible 1, the submersible 1 will move in a direction different from the direction instructed by the pilot P. In this case, the display processing unit 251 will display a warning message on the display unit 22 indicating that the submersible 1 is moving in a direction different from the direction instructed by the pilot P (for example, a message such as "In response to the instruction to move to the right sideways, it has moved diagonally down to the right!"). The warning message may also be, for example, a message such as "Thruster N is being stopped," or "Thruster N is being reversed."

[0082] When the signal generation unit 252 receives an input instruction from the operation unit 23 to generate a control signal, it generates a control signal to control the propulsion unit 12 of the submersible 1 and transmits the generated control signal to the submersible 1. This allows the submersible 1 to move normally, for example, when no object is detected near the propulsion unit 12.

[0083] [Process flow according to this embodiment] Figure 7 is a flowchart showing the processing flow according to this embodiment. The sensor 13 provided on the propulsion unit 12 of the underwater submersible 1 inputs detection data indicating the detected result to the object detection unit 162 (S1).

[0084] The object detection unit 162 detects the target object based on the input detection data and determines whether or not the target object is within a first distance from any of the multiple thrusters (S2). If there is no target object within the first distance (NO in S2), the process returns to S1.

[0085] If there is a target object within the first distance (YES in S2), the propulsion control unit 163 determines whether the thruster control setting is set to stop the thruster (S3). If the setting is set to stop the thruster (YES in S3), the propulsion control unit 163 stops the thruster for a certain period of time (S4).

[0086] If the thruster is not set to stop (NO in S3), the propulsion control unit 163 rotates the thruster in the reverse direction for a certain period of time (S5). In this way, the propulsion control unit 163 can prevent the thruster from becoming entangled with the detected object by stopping or reversing the rotation of the thruster when the detected object is nearby.

[0087] The propulsion control unit 163 determines whether a predetermined time has elapsed since the object detection unit 162 stopped detecting an object within a first distance from any of the thrusters by stopping or reversing the thrusters (S6). If the predetermined time has not elapsed (NO in S6), the propulsion control unit 163 continues to stop or reverse the thrusters.

[0088] If a predetermined time has elapsed (YES in S6), the propulsion control unit 163 restarts the rotation of the thrusters (S7). This allows the submersible 1 to resume diving in the planned direction.

[0089] [Effect of Submersible 1] As explained above, when the submersible 1 detects that a target object is near any of its multiple propulsion units 12, it can control the propulsion unit 12 that is near the target object so that the target object does not approach the propulsion unit 12. This reduces the burden on the pilot P and prevents damage to the submersible 1 caused by the propulsion unit 12 becoming entangled with the object.

[0090] Furthermore, because the submersible 1 can automatically control the system to prevent the detected object from approaching the propulsion unit 12, it is possible to prevent the propulsion unit 12 of the submersible 1 from entangling objects even in areas with low visibility, such as the sea, lakes, and rivers, where it is difficult for the pilot P to check the underwater conditions from the camera footage.

[0091] Furthermore, the submersible 1 controls the target propulsion unit 12 to generate thrust again when the detected object that has approached the propulsion unit 12 moves away from the propulsion unit 12. As a result, the submersible 1 can quickly resume diving in the planned direction, thus stabilizing the diving time and diving route.

[0092] <Second Embodiment> [Overview of Control System S] In the first embodiment, an example was described in which the propulsion control unit 163 performs control to prevent the detected object from approaching the propulsion unit 12, in response to an instruction from the object detection unit 162 that has detected the object to be detected. In other words, an example was described in which, when the submersible 1 detects an object to be detected, it automatically performs control to prevent the detected object from approaching the propulsion unit 12.

[0093] In the second embodiment, an example is described in which the submersible 1 notifies the pilot P that a target object is present near the propulsion unit 12, and the pilot P, upon receiving the notification, gives instructions for control to prevent the target object from approaching the propulsion unit 12.

[0094] [Configuration and operation of submersible vehicle 1] Figure 8 shows an example of another configuration of the underwater submersible 1.

[0095] When the object detection unit 162 detects that an object is within a first distance from any of the multiple propulsion units 12, it inputs object information indicating the detected object to the submersible communication unit 11. The object information includes, for example, that a target object has been detected, as well as information indicating the type, volume, shape, and image of the detected object.

[0096] The submersible communication unit 11 transmits the input object information to the external device 2 on the ship 3. As a result, as will be described in detail later, the pilot P on the ship 3 can determine that an object is within a first distance from any of the multiple propulsion units 12. The submersible communication unit 11 receives a control signal from the external device 2 to control the target propulsion unit 12 that has the detected object within the first distance.

[0097] The propulsion control unit 163 controls the target propulsion unit 12 in accordance with the received control signal so that the detected object does not approach the multiple propulsion units 12. For example, the propulsion control unit 163 controls the target propulsion unit 12 so that the detected object does not approach the multiple propulsion units 12 within a second distance, which is less than or equal to the first distance. The second distance may be the second distance determined by the distance determination unit 161 or the second distance stored in the storage unit 15, as in the first embodiment, or it may be the second distance specified by the pilot P by inputting it into the external device 2.

[0098] [Configuration and operation of external device 2] Referring to the external device 2 shown in Figure 6, the configuration and operation of the external device 2 will be explained.

[0099] The device communication unit 21 receives object information from the underwater submersible 1 indicating a target object within a first distance from any of the multiple propulsion units 12. The device communication unit 21 inputs the received object information to the display processing unit 251.

[0100] The display processing unit 251 displays on the display unit 22 that a target object has been detected, as well as the type, volume, shape, and image of the detected object, based on the input object information. This allows the pilot P on the ship 3 to understand that an object is within a first distance from any of the multiple propulsion units 12, as well as the type, volume, shape, and image of the object.

[0101] Pilot P checks the type, volume, shape, and image of the object, and if he determines that it is necessary to take control to prevent the detected object from approaching the propulsion unit 12, he performs an operation on the control unit 23 to generate a control signal for that control. When the control unit 23 receives the operation to generate a control signal from pilot P, it inputs the instruction to generate a control signal to the signal generation unit 252.

[0102] When the signal generation unit 252 receives an instruction to generate a control signal from the operation unit 23, it generates a control signal to control the target propulsion unit 12 of the submersible 1 and inputs the generated control signal to the device communication unit 21. The device communication unit 21 transmits the input control signal to the submersible 1.

[0103] [Effect of Submersible 1] As described above, in the second embodiment, when pilot P receives notification from the submersible 1 that a target object is present near the propulsion unit 12, he can check the type, volume, shape, and image of the target object and decide whether or not to perform control to prevent the target object from approaching the propulsion unit 12. As a result, for example, in the case of a false detection, or when pilot P, based on his experience, determines that the probability of the target object being caught in the propulsion unit 12 is low, pilot P can decide not to perform control to prevent the target object from approaching the propulsion unit 12. As a result, the operation of the propulsion unit 12 becomes stable, and the submersible 1's diving time and diving route become stable.

[0104] Furthermore, this invention will make it possible to contribute to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs), "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation."

[0105] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of its gist. For example, all or part of the apparatus can be configured by functionally or physically distributing and integrating in any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combinations are combined with the effects of the original embodiments. [Explanation of Symbols]

[0106] 1 Underwater submersible 11 Submarine Communication Department 12 Promotion Department 13 sensors 14 Current meter 15 Storage section 16 Control Unit 161 Distance determination unit 162 Object detection unit 163 Propulsion Control Unit 2 External device 21. Device Communication Unit 22 Display section 23 Control section 24 Memory section 25 Control Unit 251 Display Processing Unit 252 Signal Generation Unit S Control System

Claims

1. Multiple propulsion units that generate thrust to propel a submersible underwater vehicle, An object detection unit that detects the target object, When the object detection unit detects that the object to be detected is within a first distance from any of the multiple propulsion units, the propulsion control unit controls the target propulsion unit that has the object to be detected within the first distance, so as to prevent the object to be detected from approaching the multiple propulsion units. A submersible vehicle having a submersible body.

2. The propulsion control unit controls the target propulsion unit so as not to generate the propulsion force. The underwater submersible according to claim 1.

3. The propulsion control unit controls the target propulsion unit to generate a propulsion force that propels the submersible in a direction different from the propulsion direction that was propelling the submersible at the time the object detection unit detects the target object. The underwater submersible according to claim 1.

4. The propulsion control unit controls the target propulsion unit while the submersible is being propelled in the direction that propelled the submersible at the time the object detection unit detected the target object, and then, when the object detection unit no longer detects that the target object is within the first distance from any of the multiple propulsion units, it controls the target propulsion unit to generate the propulsion force that propels the submersible after a predetermined time has elapsed from the time when it no longer detects the target object. The underwater submersible according to claim 1.

5. The propulsion control unit controls the target propulsion unit while the submersible is being propelled in the direction that propelled the submersible at the time the object detection unit detected the target object, and then controls the target propulsion unit to generate the propulsion force that propels the submersible when the detected object is separated from any of the multiple propulsion units by a third distance or more greater than the first distance. The underwater submersible according to claim 1.

6. The propulsion control unit controls the target propulsion unit so that the detected object does not approach the multiple propulsion units if at least one of the type, shape, or volume of the detected object detected by the object detection unit to be within a first distance from any of the multiple propulsion units meets a predetermined criterion. The underwater submersible according to claim 1.

7. The propulsion control unit controls the target propulsion unit so that the detected object does not approach the multiple propulsion units when the detected object detected by the object detection unit is within the first distance associated with the detected object in a distance management table in which the object and the first distance are associated. The underwater submersible according to claim 1.

8. The object detection unit detects, based on detection data output from multiple object detection sensors corresponding to each of the multiple propulsion units, that the object to be detected is within the first distance from any of the multiple propulsion units. The underwater submersible according to claim 1.

9. The object detection unit detects a cable connecting an underwater submersible and an external device on a surface-navigating vehicle present on the water surface as the object to be detected, based on the shape of the object indicated by the detection data. The underwater submersible according to claim 8.

10. The object detection sensor is a magnetic sensor that detects the strength of a magnetic field. The object detection unit detects, based on the strength of the magnetic field detected by the magnetic sensor, an electric cable connecting an underwater submersible and an external device on a surface-navigating vehicle present on the water surface, as the object to be detected. The underwater submersible according to claim 8.

11. The aforementioned submersible body is A flow meter for measuring the direction and velocity of water flow, A distance determination unit that determines the first distance based on the water flow direction and flow velocity measured by the flow meter, It further possesses, The underwater submersible according to claim 1.

12. The distance determination unit determines the first distance such that the value of the first distance when the direction of water flow is from the position of the object to be detected to the position of the submersible is greater than the value of the first distance when the direction of water flow is from the position of the submersible is to the position of the object to be detected. The underwater submersible according to claim 11.

13. The distance determination unit determines the first distance such that, when the direction of the water flow is from the position of the object to be detected to the position of the underwater submersible, the greater the water flow velocity, the greater the value of the first distance. The underwater submersible according to claim 11.

14. When the object detection unit detects that the target object is within a first distance from any of the multiple propulsion units, the propulsion control unit controls the target propulsion unit so that the target object does not approach a second distance, which is less than or equal to the first distance, relative to the multiple propulsion units. The underwater submersible according to claim 1.

15. It comprises an underwater submersible that moves underwater, and an external device capable of communicating with the underwater submersible, The aforementioned submersible body is Multiple propulsion units that generate thrust to propel a submersible underwater vehicle, An object detection unit that detects the target object, A submersible communication unit transmits object information indicating the target object to be detected that is within a first distance from any of the multiple propulsion units to the external device, and receives a control signal for controlling the target propulsion unit which is the propulsion unit in which the target object to be detected is within the first distance. A propulsion control unit controls the target propulsion unit so that the detected object does not approach the plurality of propulsion units in accordance with the received control signal, It has, The external device is, A signal generation unit that generates the aforementioned control signal, A device communication unit that receives the object information from the underwater submersible and transmits the generated control signal to the underwater submersible, Having, Control system.

16. A method executed by a processor for controlling an underwater submersible having multiple propulsion units that generate thrust to propel the underwater submersible, The steps include detecting the target object and When it is detected that the object to be detected is within a first distance from any of the multiple propulsion units, the step of controlling the target propulsion unit that is the propulsion unit in which the object to be detected is located, so as to prevent the object to be detected from approaching the multiple propulsion units, A control method having

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