Recovery device

Abstract

To provide a recovery device capable of efficiently recovering underwater objects.SOLUTION: A recovery device 1 is installed in an underwater robot configured to be movable in the water and recovers underwater objects. The recovery device comprises a T-shaped pipe 3 having a horizontal part 3a with opening both end sections and a vertical part 3b extended downward from the middle of the horizontal part 3a, a propeller 6 placed at one end of the horizontal part 3a, a housing part 4 placed at the other end of the horizontal part 3a and to house the underwater objects, and a suction part 5 placed at the bottom end of the vertical part 3b and to suck in the underwater objects.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a recovery device installed in an underwater robot for recovering underwater objects, and more particularly to a recovery device capable of efficiently recovering underwater objects.

Background Art

[0002] Various underwater robots for recovering underwater organisms have been proposed (see, for example, Patent Document 1). Patent Document 1 discloses a configuration in which a recovery basket is arranged downstream of a suction port, and a pump is arranged on the downstream side of this recovery basket.

[0003] Since the flow path from the suction port to the pump was long, the pressure loss was relatively large. In addition, since the recovery basket was arranged in the middle of this flow path, the pressure loss was even greater. It was necessary to install a pump with a large output in the underwater robot.

[0004] When a pump with a large output was arranged, the flow rate of the water discharged behind the underwater robot increased, so there was a problem that the underwater robot advanced unintentionally. It was difficult to control the attitude of the underwater robot. There was a problem that the attitude of the underwater robot became unstable and the efficiency of recovering underwater organisms decreased.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a recovery device capable of efficiently recovering underwater objects.

Means for Solving the Problems

[0007] A recovery device for achieving the above objective is a recovery device installed on an underwater robot configured to move underwater to recover underwater objects, comprising a T-shaped pipe having a horizontal section with openings at both ends and a vertical section extending downward from the middle of the horizontal section, and a propeller positioned at one end of the horizontal section. Installed on the aforementioned underwater robot and The horizontal portion comprises a storage section located at the other end for accommodating submerged objects, and a suction section located at the lower end of the vertical portion for sucking in submerged objects. Furthermore, the distance from the upper end of the vertical portion to the propeller is set to be smaller than the distance from the upper end of the vertical portion to the housing portion. It is characterized by the following: [Effects of the Invention]

[0008] According to this invention, pressure loss can be suppressed because the distance from the propeller to the upper end of the vertical portion is relatively short. A propeller with relatively low output can be used. Precise attitude control of the underwater robot is possible, which is advantageous for efficiently recovering underwater objects. [Brief explanation of the drawing]

[0009] [Figure 1] This is an explanatory diagram illustrating a recovery device installed on an underwater robot. [Figure 2] Figure 1 is an explanatory diagram illustrating a recovery device. [Figure 3] Figure 2 is an explanatory diagram illustrating the top surface of the recovery device. [Figure 4] Figure 3 is an explanatory diagram illustrating the AA and BB sections. [Figure 5] Figure 2 is an explanatory diagram illustrating the fluid flow in the recovery device. [Modes for carrying out the invention]

[0010] The recovery device will be described below based on the embodiment shown in the figure. In the figure, the front-to-back direction of the underwater robot is indicated by arrow y, the width direction which intersects this front-to-back direction y at a right angle is indicated by arrow x, and the up-and-down direction is indicated by arrow z.

[0011] As illustrated in Figure 1, the recovery device 1 is installed and used on the underwater robot 2. The recovery device 1 is fixed to the underwater robot 2 so as to partially cover the top and front sides of the underwater robot 2. The underwater robot 2 can be, for example, a remotely operated vehicle (ROV) or an autonomous underwater vehicle (AUV). The following explanation will use a remotely operated underwater robot as an example. The underwater robot 2 is equipped with a propulsion mechanism 2a, such as a stunter, for moving underwater. It is also equipped with a camera 2b for acquiring images of the area around the underwater robot 2. The operator remotely operates the underwater robot 2 using a controller while checking the images from the camera 2b.

[0012] As illustrated in Figure 2, the recovery device 1 comprises a T-shaped pipe 3, which is constructed by combining cylindrical pipes, and a storage section 4 for accommodating submerged objects. The T-shaped pipe 3 has a horizontal section 3a with open ends and a vertical section 3b that extends downward from a position midway along the horizontal section 3a. The horizontal section 3a extends along the front-rear direction y, and the vertical section 3b as a whole extends along the up-down direction z. Submerged objects are sucked in from the lower end of the vertical section 3b and recovered into the storage section 4 via the horizontal section 3a. The T-shaped pipe 3 is made of synthetic resin, such as polyvinyl chloride pipe. The T-shaped pipe 3 is not limited to synthetic resin; it may also be made of metal pipe. Furthermore, the horizontal section 3a and the vertical section 3b may be made of curved pipes.

[0013] The inner diameter of the T-tube 3 is set to, for example, 150 mm or 125 mm. The inner diameter of the T-tube 3 is not limited to the above and can be set appropriately according to the size of the underwater object to be recovered. If the inner diameter of the T-tube 3 is too small, the underwater object cannot pass through. Also, if the inner diameter of the T-tube 3 is too large, it will be difficult to suck up the underwater object. Therefore, it is desirable to set the inner diameter of the T-tube 3 to be approximately the same size as the underwater object.

[0014] A suction section 5 is located at the lower end of the vertical section 3b. The suction section 5 can be made of a pipe similar to the cylindrical pipe that makes up the T-shaped pipe 3. The suction section 5 and the vertical section 3b are connected such that the inclination θ1 of the central axis c2 of the suction section 5 with respect to the central axis c1 near the lower end of the vertical section 3b is 45°. In Figure 2, for illustrative purposes, the central axis c1 of the vertical section 3b and the central axis c2 of the suction section 5 are shown by dashed lines. In this embodiment, the central axis c1 near the lower end of the vertical section 3b is set to be parallel to the vertical direction z.

[0015] The vertical section 3b is preferably made of a transparent synthetic resin pipe. This is because even if the outer diameter of the vertical section 3b is relatively large, it will be less likely to obstruct the view of the camera 2b of the underwater robot 2. Similarly, the suction section 5 is also preferably made of a transparent synthetic resin pipe. Even if the underwater robot 2 is an autonomous underwater vehicle (AUV), this will be less likely to interfere with the operation of the camera 2b for image recognition and other sensors. For this reason, it is sometimes preferable for the vertical section 3b and other parts to be made of transparent synthetic resin pipes.

[0016] As illustrated in Figures 2 and 3, a propeller 6 is positioned at one end of the horizontal section 3a of the T-tube 3. The propeller 6 is configured to rotate by receiving power from an underwater motor. The propeller 6 is configured to supply fluid from the outside into the interior of the horizontal section 3a. The propeller 6 may also be configured as a pump. In this specification, the propeller 6 is a concept that includes a pump. In this embodiment, a protective net 7 is installed on the propeller 6 to protect it. Figure 3 shows the propeller 6 with the protective net 7 removed for illustrative purposes.

[0017] The other end of the horizontal portion 3a is connected to a housing portion 4. The housing portion 4 is configured to allow fluid to pass through but not underwater objects. The housing portion 4 can be configured as a box body in which at least a part of the wall surface is formed of a mesh member such as a wire mesh. In this embodiment, the peripheral surface and the bottom surface are formed of plate-like members through which fluid does not pass, and the upper surface is formed of a mesh member 4a through which fluid passes. The housing portion 4 is not limited to a box body and may be configured as a bag body in which at least a part is formed of a mesh member such as a fibrous mesh.

[0018] As illustrated in FIGS. 3 and 4, in a cross section orthogonal to the front-rear direction y, which is the direction of travel of the fluid fed from the propeller 6, the cross-sectional area of the housing portion 4 is larger than the cross-sectional area of the horizontal portion 3a. That is, the area of the flow path through which the fluid passes is set to be larger in the housing portion 4 than in the horizontal portion 3a. In this embodiment, the housing portion 4 is formed to be larger than the horizontal portion 3a at least in the width direction x.

[0019] The underwater robot 2 equipped with the recovery device 1 is used underwater, such as in the sea, a lake, or an aquarium. The underwater robot 2 is used, for example, when recovering underwater objects such as sea urchins, which are the cause of algae burning, from the seabed. The underwater robot 2 is also used, for example, when recovering fish (dead fish) that have sunk to the bottom of a fish farm. The underwater robot 2 is used, for example, when recovering underwater objects such as garbage floating in the sea or sunk to the seabed. In this specification, underwater objects are a concept that includes underwater organisms and underwater garbage. The underwater robot 2 equipped with the recovery device 1 is first submerged in water.

[0020] When the propeller 6 is operated as illustrated in FIG. 5, a fluid flow such as seawater is generated in the T-shaped pipe 3. In FIG. 5, the direction of the fluid flow is indicated by an arrow for the sake of explanation. Along with the operation of the propeller 6, a flow from the propeller 6 toward the housing part 4 occurs in the horizontal part 3a. Due to the flow in the horizontal part 3a, the pressure at the upper end side of the vertical part 3b decreases. Along with this pressure decrease, an upward flow occurs inside the vertical part 3b. Due to this upward flow, the underwater object m is sucked in from the suction part 5. The underwater object m moves to the housing part 4 via the vertical part 3b and the horizontal part 3a. The fluid flowing into the housing part 4 passes through the net-like member 4a of the housing part 4 and is discharged to the outside of the recovery device 1.

[0021] Since the distance from the propeller 6 to the upper end of the vertical part 3b is relatively short, the pressure loss can be suppressed. A propeller 6 with a relatively small output can be used. Since the water flow generated by the propeller 6 can be suppressed to be small, it is possible to suppress the attitude of the underwater robot 2 from being disrupted by the propeller 6. Since the attitude control of the underwater robot 2 can be performed with high accuracy, it is advantageous for efficiently recovering the underwater object m.

[0022] As illustrated in FIG. 2, in the horizontal part 3a, it is desirable that the distance L2 from the upper end p to the end on the side of the propeller 6 is set smaller than the distance L1 from the upper end p to the end on the side of the housing part 4. The pressure at the upper end p of the vertical part 3b can be efficiently decreased by the flow generated by the propeller 6. Here, the upper end p of the vertical part 3b refers to the point where the central axis c3 in the vicinity of the upper end of the vertical part 3b and the wall surface of the horizontal part 3a intersect when the recovery device 1 is viewed in the width direction x. In FIG. 2, the central axis c3 is indicated by a dashed line for the sake of explanation.

[0023] As illustrated in Figure 5, the fluid sent from the propeller 6 into the recovery device 1 is discharged to the outside via the containment section 4. The fluid flow path is wider in the containment section 4 than in the T-pipe 3. As illustrated in Figure 4, it can also be said that the cross-sectional area perpendicular to the direction of fluid travel (forward / backward direction y) is larger in the containment section 4 than in the horizontal section 3a of the T-pipe 3. Therefore, the fluid flowing from the T-pipe 3 into the containment section 4 experiences a significant decrease in flow velocity. Furthermore, the fluid velocity decreases due to collisions with the walls of the containment section 4 and with underwater objects m. Because the direction of fluid flow is dispersed within the containment section 4, the force exerted by the fluid on the underwater robot 2 is reduced. In other words, the influence of the fluid flow generated in the recovery device 1 on the underwater robot 2 can be suppressed. This avoids the problem of the underwater robot 2 losing its posture due to unintended force in a specific direction. This is advantageous for efficiently recovering underwater objects m.

[0024] As illustrated in Figure 2, the horizontal portion 3a and the vertical portion 3b may be connected such that the inclination θ2 of the central axis c3 near the upper end of the vertical portion 3b with respect to the central axis c4 of the horizontal portion 3a is less than 90°. The inclination θ2 can be appropriately set, for example, within a range of less than 90° and 30° or more. In this case, the upper end of the vertical portion 3b is inclined in a direction approaching the housing portion 4. In Figure 2, the central axis c4 is shown as a dashed line for illustrative purposes.

[0025] This configuration makes it easier to avoid problems such as underwater objects m getting caught in the flow path at the junction of the horizontal section 3a and the vertical section 3b. Even if the flow velocity of the flow generated by the propeller 6 is relatively small, the fluid flows efficiently from the vertical section 3b to the containment section 4 of the horizontal section 3a. This is advantageous for miniaturizing the propeller 6.

[0026] This does not exclude the case where the inclination θ2 of the central axis c3 near the upper end of the vertical portion 3b with respect to the central axis c4 of the horizontal portion 3a is set to 90°.

[0027] It is desirable that the fluid velocity at a position inside the horizontal section 3a and between the upper end p of the vertical section 3b and the propeller 6 be set to 0.5 m / sec or more and 1.5 m / sec or less. Since the fluid velocity inside the T-tube 3 is set to be relatively low, it is advantageous for recovering the underwater object m without damaging it. The fluid velocity is not limited to the above and is set according to the size and mass of the underwater object m. It is desirable that the fluid velocity be set within a range that allows for the recovery of the underwater object m without damaging it. In other words, the fluid velocity should be set within a range that is greater than or equal to the fluid velocity at which the underwater object m can be recovered, and less than the fluid velocity at which the underwater object m is destroyed.

[0028] The recovery device 1 may be equipped with a control mechanism that controls the rotation speed of the propeller 6 according to the recovery status of the underwater object m. The recovery status of the underwater object m refers to information regarding whether or not the underwater object m can be recovered, and information regarding whether or not the underwater object m has been damaged.

[0029] The control mechanism may have a configuration that controls the rotation speed of the propeller 6 based on information acquired by the camera 2b of the underwater robot 2. For example, if an underwater object m is present near the suction section 5 but is not sucked into the suction section 5, the control mechanism increases the rotation speed of the propeller 6. When the underwater object m remains stationary near the suction section 5 for a predetermined time, such as 3 seconds, the control mechanism increases the rotation speed of the propeller 6.

[0030] The control mechanism may have a configuration that controls the rotation speed of the propeller 6 based on information acquired by a camera that photographs the storage unit 4. For example, when the underwater object m is destroyed or multiple fragments of the underwater object m are found inside the storage unit 4, the control mechanism reduces the rotation speed of the propeller 6.

[0031] If the underwater robot 2 is composed of an ROV, the control mechanism may be configured to control the rotation speed of the propeller 6 based on signals from the controller. The operator determines the recovery status of the underwater object m and inputs this determination result to the controller, thereby controlling the rotation speed of the propeller 6 based on the recovery status of the underwater object m.

[0032] Since aquatic objects such as sea urchins can be recovered without being destroyed, they can be used for food. Also, since dead fish can be recovered without being destroyed, the problem of fragments of dead fish being dispersed from the containment unit 4 into the water and contaminating the water outside the containment unit 4 can be avoided.

[0033] The control mechanism may have a configuration that controls the rotation speed of the propeller 6 according to the size of the underwater object m to be recovered. In this case, the flow velocity generated by the propeller 6 is set to a range where it is greater than or equal to the flow velocity at which underwater objects m of the size to be recovered can be recovered, and less than or equal to the flow velocity at which underwater objects m smaller than the target cannot be recovered. This prevents the recovery of underwater objects m smaller than the target object m. The recovery device 1 can recover only large, fully grown sea urchins while avoiding the recovery of small, immature sea urchins. This prevents overfishing of sea urchins by the recovery device 1. Larger sea urchins have greater buoyancy than smaller sea urchins, making them easier to recover with the recovery device 1 even at low flow velocities.

[0034] If the flow velocity at which a submerged object m smaller than the target object becomes unrecoverable is lower than the flow velocity at which the submerged object m is destroyed, the upper limit of the flow velocity is set to the flow velocity at which a submerged object m smaller than the target object becomes unrecoverable. If the flow velocity at which the submerged object m is destroyed is lower, the upper limit of the flow velocity is set to a value lower than the flow velocity at which the submerged object m is destroyed. In either case, it is possible to avoid recovering a submerged object m smaller than the target object while also avoiding the destruction of the submerged object m.

[0035] It is desirable that the inner diameters of the horizontal section 3a and the vertical section 3b be set to the same size. By keeping the inner diameters constant in the horizontal section 3a and the vertical section 3b, the fluid velocity can be stabilized. Since the fluid velocity does not change abruptly inside the T-tube 3, it is advantageous in avoiding problems such as the submerged object m being destroyed or becoming clogged in the flow path.

[0036] The fluid velocity between the upper end p of the vertical section 3b and the propeller 6 is not limited to the above. It can be appropriately changed depending on the inner diameter of the T-tube 3, the type and size of the underwater object m to be recovered, and the purpose of recovery.

[0037] The inclination θ1 of the central axis c2 with respect to the central axis c1, as illustrated in Figure 2, should preferably be set within the range of 30° to 90°. Setting the inclination θ1 to an angle close to 90° makes it easier to suck underwater objects m located in front of the suction section 5 into the suction section 5. Once the underwater object m enters the suction section 5, even partially, it can then be easily sucked up to the horizontal section 3a. Setting the inclination θ1 to an angle close to 30° makes it easier to avoid problems such as relatively large dead fish getting stuck in the suction section 5.

[0038] Multiple suction sections 5 with different inclinations θ1 may be prepared in advance, and the suction sections 5 can be switched relative to the T-pipe 3. By replacing the suction section 5 with the appropriate one according to the recovery status of the underwater object m, work efficiency can be improved. The lower end of the vertical section 3b may also be used as the suction section 5. In this case, the inclination θ1 becomes 0°.

[0039] Multiple T-shaped pipes 3 with different inner diameters may be prepared in advance, and the underwater robot 2 may be able to switch between the T-shaped pipes 3. By replacing the T-shaped pipe 3 with one having an appropriate inner diameter according to the size of the underwater object m to be recovered, work efficiency can be improved.

[0040] The containment section 4 may have its circumferential surface, bottom surface, and top surface made of mesh material 4a. Alternatively, only a part of the circumferential surface or a part of the bottom surface may be made of mesh material 4a. As illustrated in Figure 3, only the top surface of the containment section 4 may be made of mesh material 4a. In this case, fluid will be discharged only from the top surface of the containment section 4. Since the flow velocity of the fluid discharged from the containment section 4 is inherently small, the underwater robot 2 will experience almost no force from the discharged fluid. Even if the underwater robot 2 does experience a force from the discharged fluid, it will be a downward force. For example, when the underwater robot 2 is working on the seabed, a downward force on the underwater robot 2 will have almost no effect on the work. This is advantageous for efficiently recovering underwater objects m.

[0041] Furthermore, since the surrounding surface and bottom surface of the containment section 4 are configured in a way that prevents fluid from passing through, fluid does not pass from one side of the containment section 4 to the other. This prevents the underwater object m from being subjected to force and damaged by fluid passing through the mesh member 4a when the underwater robot 2 moves. This allows for an improvement in the movement speed of the underwater robot 2, which is advantageous for improving the work efficiency in the recovery of underwater objects m.

[0042] A wave-dissipating plate may be placed near the mesh member 4a to obstruct the fluid flow. The wave-dissipating plate can be placed inside or outside the containment section 4, or both. This can suppress the fluid velocity discharged from the containment section 4 to the outside. This is advantageous for efficiently recovering the underwater object m. It can also suppress the passage of fluid from one side of the containment section 4 to the other. This can improve the movement speed of the underwater robot 2 while suppressing damage to the underwater object m. [Explanation of symbols]

[0043] 1. Recovery device 2 Underwater robots 2a Propulsion mechanism 2b camera 3 T-tube 3a horizontal part 3b Vertical section 4. Storage area 4a Mesh member 5. Suction section 6 propellers 7. Protective net x width direction y: forward / backward direction z Vertical direction c1-4 Center axis θ1-2 slope m Underwater objects p (upper part of the vertical section) L1-2 distance

Claims

1. In a recovery device installed on an underwater robot configured to move underwater, for recovering objects underwater, It comprises a T-shaped pipe having a horizontal section with openings at both ends and a vertical section extending downward from the middle of the horizontal section, a propeller positioned at one end of the horizontal section, a storage section installed on the underwater robot and positioned at the other end of the horizontal section for accommodating underwater objects, and a suction section positioned at the lower end of the vertical section for sucking up underwater objects. A recovery device characterized in that the distance from the upper end of the vertical portion to the propeller is set to be smaller than the distance from the upper end of the vertical portion to the storage portion.

2. The recovery device according to claim 1, wherein the fluid velocity at a position inside the horizontal portion and between the upper end of the vertical portion and the propeller is set to 0.5 m / sec or more and 1.5 m / sec or less.

3. The recovery device according to claim 1 or 2, further comprising a control mechanism that controls the rotation speed of the propeller based on information acquired by the camera of the underwater robot or by a camera that photographs the housing.

4. The recovery device according to claim 1 or 2, wherein the storage section is composed of a plate-like member whose circumferential and bottom surfaces are not permeable to fluid, and whose upper surface is composed of a mesh-like member through which fluid can pass.

Images