Method and apparatus for filling dynamic buoyancy system for deep sea mining vehicle

Abstract

A buoyancy system for an autonomous underwater vehicle is provided. The buoyancy system includes one or more spherical pressure vessels, where each vessel includes two hemispherical pieces mechanically or adhesively connected together at a seam joint. Further, each container includes one or more bulkhead perforations for connecting the container to an external component and a sensor of the buoyancy system. The buoyancy system further comprises: (i) a main pump connected to at least one of the one or more containers for pumping seawater from the one or more containers; (ii) a pressure sensor connected to at least one of the one or more containers; and (iii) a level sensor extending through all of the spherical pressure vessels or the first subset of the one or more spherical pressure vessels to detect the level of seawater inside the one or more vessels.

Description

[0001] Cross-references to related applications This application claims the benefit and priority of U.S. Patent Application No. 18 / 352,038, filed July 13, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure generally relates to deep-sea mining systems, and more specifically, to dynamic buoyancy systems implemented within deep-sea mining systems. These dynamic buoyancy systems employ variable buoyancy conditions that allow the deep-sea mining systems to descend, collect ore nodules from the seabed, and ascend without contacting the seabed, thereby limiting environmental impact. Background Technology

[0003] As the world transitions to green energy solutions, there is a growing demand for storing energy in reusable batteries made from critical metals such as nickel, copper, and cobalt. Currently, terrestrial sources of these metals are scarce, and these land-based resources may be located in hard-to-reach places and / or within sensitive ecosystems. Deep-sea mining, an untapped source of critical metals in the form of ore nodules (e.g., polymetallic ferromanganese nodules), has become a focus of the mining industry in recent years.

[0004] Technical challenges associated with deep-sea mining include the ocean depths (e.g., 5 km to 6 km) and extreme pressures (e.g., between 500 and 600 bar) required for mining ore nodules, and the technologies needed to transport the mined ore to the ocean surface. Two systems have been extensively studied and identified as feasible on a small scale: (i) a seabed dredging collector system that pumps the ore to the surface as slurry via a vertical riser; and (ii) a mechanical lifting system that uses synthetic fiber ropes. However, both systems suffer from reliability and scalability issues and can cause irreparable damage to sensitive environments due to disturbances to the seabed during the mining process.

[0005] Therefore, there is a need to extract minerals from the seabed in a more sustainable way while maintaining the integrity of the seabed ecosystem. Summary of the Invention

[0006] This document discloses a dynamic buoyancy system implemented for deep-sea mining systems and its usage methods. According to some embodiments, the disclosed dynamic buoyancy system enables the deep-sea mining system to hover at a predetermined distance above the seabed throughout the mining process, minimizing the environmental impact of the mining operation. Furthermore, the deep-sea mining system using the dynamic buoyancy system disclosed herein does not rely on dredging or mud risers to collect and transport ore to the ocean surface, and can be arranged and deployed in a redundant fleet of vehicles. According to some embodiments, the dynamic buoyancy system enables the deep-sea mining system to descend to the seabed, travel along the seabed without contact with the seabed while collecting ore nodules, and rise to the surface to deliver the payload of the deep-sea mining system. The dynamic buoyancy system employs variable buoyancy technology and utilizes a large pressure vessel designed to operate at a planned ocean depth while the deep-sea mining system descends, collects ore, and rises without contacting the seabed and with minimal environmental harm. Attached Figure Description

[0007] The accompanying drawings, which are included as part of this specification, illustrate presently preferred embodiments and, together with the general description given above and the detailed description of preferred embodiments given below, serve to explain and teach the principles described herein.

[0008] Figure 1 An exemplary deep-sea mining system according to some embodiments is illustrated.

[0009] Figure 2 The illustration shows a dynamic buoyancy system implemented in a deep-sea mining system according to some embodiments.

[0010] Figure 3 The operation of a dynamic buoyancy system implemented in a deep-sea mining system according to some embodiments is described.

[0011] Figure 4 This is an exemplary arrangement of a dynamic buoyancy system with multiple pressure vessels, implemented in a deep-sea mining system according to some embodiments, wherein the multiple pressure vessels form a corresponding dynamic buoyancy subsystem.

[0012] Figure 5 This is a top view of an array of dynamic buoyancy subsystems implemented in a deep-sea mining system according to some embodiments.

[0013] Figure 6 It is a spherical pressure vessel according to some embodiments.

[0014] Figure 7 This is an exemplary vertical configuration of a spherical pressure vessel according to some embodiments.

[0015] Figure 8It is an exemplary three-dimensional configuration (array) of a spherical pressure vessel according to some embodiments. Detailed Implementation

[0016] Figure 1 An exemplary deep-sea mining system 100, deployed from a mining vessel 110 according to some embodiments, is illustrated for collecting ore nodules 120 disposed on the seabed. The deep-sea mining system 100 descends to near the seabed and hovers above the seabed during the ore collection process. In some embodiments, the deep-sea mining system 100 includes an autonomous underwater vehicle (UAV) 130, an ore collection system 140, a payload hopper 150, and a dynamic buoyancy system 160. The ore collection system 140 collects ore nodules 120 from the seabed, the payload hopper 150 is used for temporary storage of the collected ore, and the dynamic buoyancy system 160 enables the deep-sea mining system 100 to move primarily in the vertical direction (e.g., descending from the ocean surface to the seabed and rising from the seabed to the ocean surface).

[0017] According to some embodiments, the UAV 130 is equipped with thrusters (in... Figure 1 (Not shown in the diagram) This thruster enables the deep-sea mining system 100 to move primarily in the lateral direction (e.g., parallel to the seabed—along the xy plane) and secondarily in the vertical direction (e.g., along the z direction). By way of example and not limitation, the ore collection system 140 may be equipped with one or more robotic arms 140a that can extend toward the seabed and retrieve ore nodules. In some embodiments, when the deep-sea mining system 100 is hovering above the seabed, the robotic arms 140a can collect ore nodules by picking them up and placing them into the payload hopper 130 via a conveyor belt, suction system, or any other suitable means, method, or technique.

[0018] According to some embodiments, the deep-sea mining system 100 uses an underwater survey and inspection system to identify the location of ore nodules 120 on the seabed and determine whether marine organisms are attached to the nodules. By way of example and not limitation, the deep-sea mining system 100 may be configured to avoid collecting ore nodules with attached marine organisms. Once the payload hopper 150 is full, a dynamic buoyancy system 160 enables the deep-sea mining system 100 to rise to the ocean surface and deliver its payload.

[0019] According to some embodiments, components of the deep-sea mining system 100 (e.g., dynamic buoyancy system 160, payload hopper 150, ore collection system 140, and UAV 130) operate collaboratively. In some embodiments, these components may be integrated into a housing or may operate as detachable modules physically and communicatively connected to each other. According to some embodiments, during the collection / mining process, the dynamic buoyancy system 160, payload hopper 150, ore collection system 140, and UAV 130 are physically attached to each other, and during the mining and ascent processes, at least the payload hopper 150 and the dynamic buoyancy system 160 may be physically attached to each other. In some embodiments, the dynamic buoyancy system 160 may provide the necessary buoyancy during the mining process and during the ascent of at least the payload hopper 150 or the entire deep-sea mining system 100 to compensate for the collected ore. In some embodiments, if the dynamic buoyancy system 160 and the payload hopper 150 rise to the ocean surface on their own, the UAV 130 can use its thrusters to provide the necessary buoyancy to the deep-sea mining system 100 until the dynamic buoyancy system 160 and the payload hopper 150 descend from the ocean surface again to reattach to the deep-sea mining system 100.

[0020] In some embodiments, the deep-sea mining system 100 may include additional components, modules, and systems required for its operation. For simplicity, Figure 1 These additional components, modules, and systems are not shown. By way of example and not limitation, these additional components, modules, and systems may include cables, one or more onboard computers, electronic devices, additional propulsion systems, motors, batteries, communication equipment, cameras, radar, controllers, GPS, etc. All of these additional components, modules, and systems are within the spirit and scope of this disclosure. In some embodiments, the deep-sea mining system 100 may operate in autonomous mode, semi-automatic mode, manual mode, or a combination of the above modes in accordance with instructions from the mining vessel 110. In yet another embodiment, the deep-sea mining system 100 may be communicatively coupled to and physically connected to the mining vessel 110 via ropes, cables, etc.

[0021] According to some embodiments, in Figure 2 Details of the dynamic buoyancy system 160 are shown in the image. Figure 2As shown, the dynamic buoyancy system 160 includes a pressure vessel 200, buoyancy foam material 210, a main pump 220, a controller 230 capable of receiving and transmitting data, and a power supply 240 having a charging port 240a. According to some embodiments, all components of the dynamic buoyancy system 160 are designed to operate at ocean depths between approximately 5 km and 6 km. However, this is not limiting, and the dynamic buoyancy system 160 can be configured to operate at ocean depths greater than 6 km or less than 5 km. In some embodiments, the pressure vessel volume can be selected based on the target mineral payload weight. For example, a larger payload weight requires a higher pressure vessel volume compared to a smaller payload weight.

[0022] like Figure 2 As shown, pressure vessel 200 contains both a compressible gas (e.g., air, filtered air, or other suitable gas or gas mixture) and an incompressible liquid (e.g., seawater, filtered seawater, desalinated seawater, deionized water, or other suitable liquid), indicated by gray shading. In some embodiments, in addition to the main pump 220, dynamic buoyancy system 160 may also include one or more secondary pumps. For example, an optional gas pump 250 for gas pressurization may be attached to valve 260 to pre-fill pressure vessel 200 with compressible gas at the ocean surface. According to some embodiments, valve 260 may allow gas to enter pressure vessel 200 and prevent liquid and gas from escaping pressure vessel 200. Additionally, when dynamic buoyancy system 160 is at a mining depth (e.g., between 5 km and 6 km), valve 260 may prevent seawater from entering pressure vessel 200. As used herein, the term “optional” is intended to mean that gas pump 250 may always be attached to pressure vessel 200 (e.g., via valve 260), or may not always be attached to pressure vessel 200 (e.g., via valve 260). For example, gas pump 250 may be located on mining vessel 110 and may be connected to pressure vessel 200 via valve 260 when buoyancy system 160 is at the sea surface, and subsequently disconnected from pressure vessel 200 when buoyancy system 160 is ready to descend. In another example, gas pump 250 may remain attached to pressure vessel 200 via valve 260 during descent and mining operations (e.g., always attached to pressure vessel 200). In some examples, low-pressure subsea liquid pump 270 may be attached to valve 280 to pump incompressible liquid to pressure vessel 200 at the sea surface. In some embodiments, subsea liquid pump 270 may introduce liquid into pressure vessel 200 during descent or during mining operations, as incorporated herein by reference. Figure 3As discussed, and not as a limitation, the submersible liquid pump 270 is capable of supplying liquid at a pressure of approximately 200 psi. Furthermore, the submersible liquid pump 270 may be uninsulated and may be permitted to dissipate the heat generated through its operation into the ocean.

[0023] In some embodiments, the main pump 220 is a high-pressure, low-volume (HPLV) pump designed to pump incompressible liquids from a pressure vessel 200 (e.g., via valve 290) at a depth corresponding to an ambient seawater pressure of approximately 600 bar. In some embodiments, the main pump 220 may be a high-power output pump (e.g., having an output power of approximately 300 hp), the pumping rate of which may be matched to the ore collection rate. By way of example, and not limitation, the pumping rate of the main pump 220 may be at least 4 liters per second. By way of example, and not limitation, the main pump 220 may be a single-stage pump or a multi-stage pump.

[0024] The pump described above can be powered by a rechargeable power supply 240, which can be charged via charging port 240a when the dynamic buoyancy system 160 is on the ocean surface. According to one embodiment, the power supply 240 can be a 400 kWh rechargeable battery. By way of example and not limitation, the power supply 240 can be a lithium iron phosphate (LiFePO4) battery. However, any suitable rechargeable battery can be used depending on the required cycle durability and energy density requirements.

[0025] According to some embodiments, Figure 1 The deep-sea mining system 100 shown can estimate its ore collection rate by measuring, for example, the mass of ore collected in the payload hopper 150 via its instruments. Accordingly, the dynamic buoyancy system 160 can adjust the buoyancy of the deep-sea mining system 100 using the estimated collection rate. Simultaneously, and if necessary, the UAV 130 can activate its thrusters to keep the deep-sea mining system 100 within an operating distance from the seabed (e.g., within the effective range of the robotic arm 140a). In some embodiments, the total thrust from the UAV 130 can be fed forward to the dynamic buoyancy system 160, allowing the dynamic buoyancy system 160 to adjust the buoyancy of the deep-sea mining system 100 to reduce the total vertical thrust compensation from the UAV 130.

[0026] refer to Figure 2The controller 230 may be configured to receive instrument readings from the deep-sea mining system 100—such as pressure readings, temperature readings, volume readings, mass readings, collection rates, and other types of rates. The controller 230 may also be configured to receive / transmit data within the dynamic buoyancy system 160, transmit data to and from the dynamic buoyancy system 160, and operate pumps (e.g., gas pump 250 and subsea liquid pump 270) and valves (e.g., valves 260, 280, and 290) in response to weight changes caused by the ore collection process. In another embodiment, the controller 230 may include a standard processing device, such as a single-board computer similar to a Raspberry Pi, or an ARM processor.

[0027] According to some embodiments, the dynamic buoyancy system 160 is also equipped with sensors (in... Figure 2 (not shown in the figure) to continuously monitor the pressure inside the pressure vessel 200, the flow rate of the liquid through the pipes, the temperature of the controller 230, the temperature of the pumps (e.g., gas pump 250 and submersible liquid pump 270), and the temperature of the power supply 240.

[0028] In some embodiments, the buoyancy foam material 210 can provide static buoyancy to compensate for the mass of the dynamic buoyancy system 160, such that when the deep-sea mining system 100 is at a target depth (e.g., between approximately 5 km and 6 km), the dynamic buoyancy system 160 itself is in a neutral buoyancy state. By way of example and not limitation, the buoyancy foam material 210 can be a synthetic foam material—e.g., hollow glass microspheres (microspheres) cast in resin. Adding buoyancy foam material to the dynamic buoyancy system 160 can increase buoyancy. Neutral buoyancy can be achieved by adding sufficient buoyancy foam material 210 such that the upward force caused by the water displacement induced by the buoyancy foam material 210 and the pressure vessel 200 compensates for the mass of the dynamic buoyancy system 160.

[0029] In other embodiments, the deep-sea mining system 100 may include a buoyancy system having one or more (e.g., multiple) pressure vessels 200, such as in Figure 4 The examples are presented in an illustrative rather than restrictive manner. Figure 4 In an exemplary configuration, pressure vessel 200 may be connected via a central manifold 400 to a single pair of pumps 220 and controllers 230. Additionally, each of the pressure vessels 200 may be equipped with its own valves 260, 280, and 290, wherein each valve 290 is connected to the central manifold 400. Figure 4For simplicity, the gas pump 250, the underwater liquid pump, and the buoyancy foam material 210 are omitted. According to some embodiments, each pressure vessel 200 connected to a common main pump 220 and controller 230 pair forms a dynamic buoyancy subsystem 400.

[0030] As an example, the deep-sea mining system 100 may be equipped with a buoyancy system having 21 pressure vessels 200 arranged in an array, each pressure vessel 200 forming a dynamic buoyancy subsystem 400, the dynamic buoyancy subsystem 400 being arranged in a 3 x 7 array, such as... Figure 5 As shown, the Figure 5 yes Figure 1 The image shows a top view of the deep-sea mining system 100 along line AB. In some embodiments, Figure 4 and Figure 5 Each dynamic buoyancy subsystem 400 can be independently controlled via its valves 260, 280, and 290. It should be understood that, depending on the size of the deep-sea mining system 100 and the payload weight it needs to carry, fewer or more buoyancy systems 400 can be used in any suitable configuration (e.g., fewer or more than 21). That is, Figure 4 and Figure 5 The configurations shown are not limiting, but merely provide one of many possible examples and configurations. Therefore, in addition to... Figure 4 and Figure 5 In addition to the configurations and arrangements shown, there may be other configurations and arrangements, all of which are within the spirit and scope of this disclosure.

[0031] By utilizing multiple dynamic buoyancy systems as discussed above, the deep-sea mining system 100 can compensate for uneven distribution of ore nodules in the payload hopper 150. For example, uneven loading may occur when ore nodules are unevenly distributed in the payload hopper 150 (e.g., more ore may accumulate on one side of the payload hopper 150). If a single dynamic buoyancy system is used in the case of uneven loading, the thrusters of the UAV 130 located on the heavier side will have to operate continuously to keep the deep-sea mining system 100 level. In contrast, when using an array of dynamic buoyancy systems (e.g., the array of dynamic buoyancy systems 400 discussed above), buoyancy can be adjusted by operating the dynamic buoyancy system 400 located on the heavier side to keep the deep-sea mining system 100 level without the need for correction by the thrusters of the UAV 130.

[0032] Another benefit of using multiple dynamic buoyancy systems is operational redundancy. For example, in the event of a failure in one of the dynamic buoyancy systems, another dynamic buoyancy system can be activated, allowing the deep-sea mining system 100 to continue operating without interruption.

[0033] According to some embodiments, a dynamic buoyancy system (e.g., each of dynamic buoyancy system 160 or dynamic buoyancy system 400) responds to data communication from other modules and dynamically adjusts buoyancy by pumping liquid into and out of the pressure vessel 200 of the dynamic buoyancy system to meet the motion objectives of the deep-sea mining system 100. According to some embodiments, the dynamic buoyancy system can communicate with a UAV 130, which can request buoyancy rate adjustments based on thrust vector requirements, such that the deep-sea mining system 100 maintains its distance from the seabed. As used herein, the term "thrust vector" refers to the resultant force acting on the deep-sea mining system 100 at any given moment and includes the vertical buoyancy exerted by one or more dynamic buoyancy systems and the horizontal and / or vertical forces exerted by the thrusters of the UAV 130. Additionally, the dynamic buoyancy system can communicate with the ore collection system 140, which can request adjustments to buoyancy based on its sensed ore mass collection rate to maintain the deep-sea mining system 100 at a predetermined distance from the seabed without engaging the UAV 130's thrusters. This limits the energy consumption of the UAV 130. Furthermore, the dynamic buoyancy system can communicate with the mining vessel 110 (e.g., via the UAV 130 or via another module) to adjust buoyancy, allowing the deep-sea mining system 100 to be anchored at a given depth in case of inclement weather, maintenance, or other reasons.

[0034] According to some embodiments, in Figure 3 The diagram schematically illustrates and describes the operation of dynamic buoyancy system 160 (and each of dynamic buoyancy systems 400) under different buoyancy conditions. More specifically, Figure 3 This demonstrates how the liquid level (shown in gray shading) in the pressure vessel 200 can be adjusted via a dynamic buoyancy system 160 to achieve [the desired effect]. Figure 1 The deep-sea mining system 100 shown in the figure has different buoyancy conditions.

[0035] According to some embodiments, the gas pressure inside pressure vessel 200 must be sufficient such that when the entire volume of liquid is pumped out of pressure vessel 200, the gas pressure inside pressure vessel 200 is equal to or slightly lower than atmospheric pressure (i.e., between approximately 14.6 psi and approximately 3.2 psi, where 14.6 psi is atmospheric pressure), allowing main pump 220 to remain operational underwater. If the gas pressure inside pressure vessel 200 is insufficient and pressure vessel 200 is in a “vacuum state” (e.g., the pressure of pressure vessel 200 is below 3.2 psi), and there is still liquid to be pumped out, the remaining liquid will begin to evaporate, and the vapor pressure of the liquid may impair the pump’s ability to remove additional liquid from pressure vessel 200. In this “pressure vessel vacuum scenario,” dynamic buoyancy system 160 will be unable to provide the necessary buoyancy for deep-sea mining system 100.

[0036] The aforementioned "pressure vessel vacuum scenario" can be avoided by setting the initial volume and initial pressure of the gas inside pressure vessel 200 such that when all desired liquid is pumped out, the gas pressure, as estimated by the ideal gas law, is not lower than the pumpable limit of main pump 220 (e.g., not lower than about 3.2 psi). The gas pressure and the maximum internal operating pressure of pressure vessel 200 determine the minimum gas volume, and thus the maximum permissible liquid volume in pressure vessel 200. Additional gas volume can be allocated (e.g., by using a larger pressure vessel 200) to reduce the gas pressure and increase the maximum permissible liquid volume in pressure vessel 200 such that when the liquid in pressure vessel 200 is emptied, the gas pressure is equal to or higher than the minimum pumpable limit of 3.2 psi discussed above—e.g., between about 14.6 psi and about 3.2 psi. Alternatively, additional static buoyancy can be provided by increasing the amount of buoyancy foam material 210 in dynamic buoyancy system 160.

[0037] In some embodiments, when the buoyancy of the deep-sea mining system 100 is at the surface, an air volume can be used to prepare the pressure vessel 200, the air volume comprising: (i) a minimum gas volume 300, (ii) a static buoyancy gas volume 310, and (iii) a gas volume reserved for the descending mass volume 320, such as Figure 3 As shown. According to some embodiments, the minimum gas volume 300 prevents the "pressure vessel vacuum scenario" discussed above. The static buoyancy gas volume 310 is an additional gas volume that is not replaced by liquid. Therefore, the static buoyancy gas volume 310 does not provide dynamic buoyancy, but rather provides a static upward force (e.g., static buoyancy). Finally, the gas volume reserved for the descending mass volume 320 represents the gas volume replaced by liquid. As combined with Figure 2The gas in question can be pumped into the pressure vessel 200 via the gas pump 250 and valve 260. At this point, the deep-sea mining system 100 has positive buoyancy and can be used for final testing.

[0038] According to some embodiments, the dynamic buoyancy system 160 is designed such that the deep-sea mining system 100 can be in a neutral buoyancy state when the volume of liquid present in the pressure vessel 200 reaches a neutral buoyancy level. Figure 3 In the example, the neutral buoyancy level is represented by the dashed line 330. For example... Figure 3 As shown, in the "pre-descent" phase A, the volume of liquid in pressure vessel 200 is below the neutral buoyancy level 330 and the "descent mass" volume 320 (e.g., the volume occupied by the "descent mass" of the liquid). Pre-descent phase A represents the situation where the deep-sea mining system 100 is at the ocean surface and has positive buoyancy.

[0039] When the descent begins (e.g., by means of...) Figure 2 (Data communication is performed with the controller 230 shown). A liquid with a volume equal to the decreased mass volume 320 is pumped into the pressure vessel 200, such as... Figure 3 The “descent” phase B is shown in the diagram. According to some embodiments, the additional liquid volume causes the deep-sea mining system 100 to exhibit negative buoyancy. Therefore, a net downward force acts on the deep-sea mining system 100, accelerating it in the water to its terminal descent velocity. According to some embodiments, the liquid (e.g., seawater) is pumped via an underwater liquid pump 270. Figure 2 The valve 280 shown is pumped in. By controlling the volume of liquid in the pressure vessel 200, the terminal velocity of the deep-sea mining system 100 can be further controlled. For example, to reduce the terminal velocity, it can be... Figure 3 The liquid volume gradually decreases from the upper limit of the decreasing mass volume of 340 to the neutral buoyancy level of 300. (As mentioned above...) Figure 2The liquid discussed can be pumped out via valve 290 through main pump 220. According to some embodiments, during the initial phase of descent, a downward auxiliary force can be provided to the pressure vessel until the volume of liquid inside the pressure vessel is sufficient to change the buoyancy of the pressure vessel from positive to negative. This downward auxiliary force can be provided via the thrusters of UAV 130, other external thrusters, counterweights on a crane, direct downward mechanical forces acting on the surface of mining vessel 110 or the dock, or by any suitable method. Descent may be accompanied by an increase in external water pressure. Opening inlet valve 280 allows water to enter pressure vessel 200 and compress the gas until equilibrium is reached. During the above process, pressure vessel 200 can be filled without operating underwater liquid pump 270. After the liquid level exceeds the neutral buoyancy level 330, pressure vessel 200 will continue to descend without an auxiliary force, which can be removed. When the desired gas pressure is reached (e.g., at approximately 200 psi), inlet valve 280 can be closed.

[0040] As the deep-sea mining system 100 approaches the seabed, it is instructed to pump out a sufficient volume of liquid to achieve neutral buoyancy. This removes the downward force and decelerates the system, bringing it to a stop near the seabed. Specifically, when the system reaches its target depth (e.g., between 5 km and 6 km), the main pump 220 adjusts the volume of liquid to a neutral buoyancy level 300, thus transitioning the system to a neutral buoyancy state. This ensures that the system can remain at its target depth (e.g., a predetermined distance from the seabed) with minimal energy consumption and without heavy reliance on the UAV 130's thrusters. According to some embodiments, Figure 1 The thrusters of the UAV 130 shown can be used solely for precise depth adjustments. This buoyancy state is... Figure 3 The middle stage is represented by "deceleration / neutralization / start collecting" (C).

[0041] At the target depth, the collection of ore nodules 120 can begin. During the collection process, the deep-sea mining system 100 is moved horizontally as needed (e.g., along...). Figure 1 The system travels in the xy plane (as shown) and occasionally vertically (e.g., along the z-direction) to follow the seabed profile. As the deep-sea mining system 100 collects ore nodules 120 from the seabed and adds weight, neutral buoyancy is maintained by pumping out an additional volume of liquid to compensate for the increased ore weight, such as... Figure 3The “Collection / Completion / Neutralization” phase D is shown. According to some embodiments, the required buoyancy at any given moment during the collection process can be calculated based on the estimated mining mass rate. This means that the mass or volume of the pumped liquid should match the total mass of the collected ore nodules (net mass in water). Since the ore has a lighter weight in water due to the buoyancy generated by displacing the water, the net mass in water is the reduced mass, which will generate a downward force observed and measured by the deep-sea mining system 100. The required buoyancy force can be communicated to a dynamic buoyancy system 160, which can pump the liquid at a dynamically varying rate. Figure 3 As shown, most of the liquid volume in the pressure vessel 200 is used to compensate for the maximum mass of ore loaded, while the deep-sea mining system 100 maintains a neutral buoyancy state.

[0042] According to some embodiments, the pumping rate of the liquid (based on the known density of the liquid) is proportional to the pumping rate of the pump (proportional to the pump's rotational speed) and matched to the loading rate of the collected ore mass (net ore mass in water). In some embodiments, the mass loading rate is determined by... Figure 1 The ore collection system 140 shown is calculated. As an example and not a limitation, the ore collection system 140 may estimate the mass loading rate based on: (i) visual signals from an onboard camera (e.g., via computer vision), (ii) electrical power measurements from a conveyor belt that can track the mass of the collected ore, or (iii) other suitable volumetric or mass measuring instruments (e.g., deflection sensors) configured to provide mass estimation.

[0043] According to some embodiments, any difference between the estimated ore mass and the actual ore mass will result in a buoyancy error, which can be immediately compensated for by the thrusters of the UAV 130. As discussed above, the thruster's response to the buoyancy error is fed forward to the dynamic buoyancy system 160 to adjust the pumping rate of the main pump 220. According to some embodiments, the deep-sea mining system 100 maintains a neutral buoyancy state during and after the collection process.

[0044] Once the deep-sea mining system 100 has reached its maximum load capacity and needs to ascend, the dynamic buoyancy system 160 is required (e.g., via data communication with controller 230) to pump (e.g., via main pump 220) a liquid volume equal to the rising mass volume of 350. This allows the deep-sea mining system 100 to gain positive buoyancy and rise toward the sea surface with the ore payload at terminal velocity. Figure 3The diagram schematically illustrates the "rising" phase E. According to some embodiments, a reserve liquid mass volume can be set to ensure the main pump 220 operates as intended and to balance the ore load when needed. This reserve liquid volume is... Figure 3 The figure shows an additional mass volume of 360.

[0045] In some embodiments, when it is desired to temporarily "park" the deep-sea mining system 100 during ascent or descent without prolonged energy consumption, data communication with the controller 230 can instruct the dynamic buoyancy system 160 to pump in or out liquid (as appropriate) to achieve neutral buoyancy. This process can be reversed when the journey resumes.

[0046] It should be understood that the dynamic buoyancy system described herein is not limited to deep-sea mining systems, but can be implemented in any type of underwater vehicle operating autonomously, semi-autonomously, or manually at any operating depth. Furthermore, the dynamic buoyancy system described herein is not limited to underwater vehicles carrying payloads.

[0047] The operating principles described in this paper for the dynamic buoyancy system 160 can be directly applied to deep-sea mining systems equipped with multiple pressure vessels 200, similar to... Figure 4 and Figure 5 The dynamic buoyancy system 400 is shown. In the case of multiple dynamic buoyancy systems, each dynamic buoyancy system can be controlled independently. Alternatively, the dynamic buoyancy systems can be divided into subgroups that can be controlled independently. For example, in... Figure 4 In a 3 x 7 arrangement, the 21 dynamic buoyancy systems can be divided into three subgroups (e.g., a 3 x 2 subgroup, a 3 x 3 subgroup, and another 3 x 2 subgroup), wherein each subgroup operates independently of the other subgroups. These variations and arrangements, as well as other similar variations and arrangements, are all within the spirit and scope of this disclosure.

[0048] Figures 1 to 4 Pressure vessel 200 is illustrated as having a cylindrical shape. However, this is not limiting, and the pressure vessel disclosed herein can have a spherical shape, similar to... Figure 6 The pressure vessel 600 shown is illustrated. Figure 6 In one example, the pressure vessel 600 is formed of two glass hemispheres glued or mechanically held together at a joint. According to some embodiments, the spherical pressure vessel 600 can be in a similar manner to... Figure 2 The cylindrical pressure vessel 200 shown is connected and constructed in the manner described. And with... Figure 2Similar to the cylindrical pressure vessel shown, pressure vessel 600 is capable of withstanding external pressures between 500 bar and 600 bar. A bulkhead penetration or port 610 can be used to connect pressure vessel 600 to various instruments and equipment, such as valve 280, pressure sensor 620, and main pump 220 (e.g., Figure 2 (As shown). The pressure vessel 600 is also equipped with a level sensor 620 that extends through the entire vertical height of the pressure vessel 600 and is configured to detect the level of the contained liquid (e.g., seawater) between the highest and lowest levels, and thus detect the volume of the contained liquid.

[0049] According to some embodiments, the spherical pressure vessel 600 is to be with Figure 3 The pressure vessel 200 shown operates in the same manner and in the same way as... Figure 2 The pressure vessel 200 shown is connected to peripheral devices such as instruments, valves, pumps, controllers, and power supplies in a similar manner. In some embodiments, one of the bulkhead penetrations 610 may function as a vent for exposing the pressure vessel 600 to the atmosphere when it is at sea level. In other embodiments, some bulkhead penetrations 610 are configured as mechanical connections to pipes; electrical connections to other components, sensors, etc.; or combinations thereof.

[0050] It should be understood that, Figure 6 The location of the bulkhead penetration 610 shown is exemplary and therefore not limiting. Thus, the location of the bulkhead penetration 610 may differ from other locations without departing from the spirit and scope of this disclosure. Figure 6 The location of the bulkhead penetration 610 is shown. Furthermore, the number of bulkhead penetrations 610 can be more or less. For example, a bulkhead penetration for a pressure sensor can be located at the bottom of the pressure vessel 600, or additional bulkhead penetrations 610 can be used to connect additional sensors for liquid or gas volume calculations.

[0051] According to some embodiments, Figure 7 An exemplary vertical configuration 700 of multiple pressure vessels 600 is shown. In this exemplary configuration 700, four pressure vessels 600 are stacked vertically on top of each other, with a single level sensor 630 extending through the entire vertical structure. This allows for the determination of the level of liquid (e.g., seawater) within the entire vertical structure. According to some embodiments, the exemplary configuration 700 may include fewer (e.g., two or three) or more (e.g., four or more) pressure vessels 600.

[0052] According to some embodiments, Figure 8An exemplary three-dimensional (3D) array 800 having multiple pressure vessels 600 is shown. Similar to... Figure 7 The configuration 700 shown includes a 3D array 800 comprising a single liquid level sensor 630 extending through the entire central vertical portion of the structure. It should be noted that the "side" pressure vessels 600 (e.g., the pressure vessels on the left and right sides of the central vertical stack) are not equipped with liquid level sensors 600; instead, they are connected to the central vertical stack via connectors A and B at the top and bottom pressure vessels 600 of the main vertical stack. According to some embodiments, the 3D array 800 is similar to... Figure 7 The configuration 700 shown is modified by adding a side pressure vessel 600. According to some embodiments, the 3D array 800 may include fewer or more pressure vessels 600 without departing from the spirit and scope of this disclosure.

[0053] According to some embodiments, the advantages of the pressure vessel disclosed herein include, but are not limited to: robust and simple single-valve filling operation, safe pressure vessel surface operation, cost-effective glass construction that allows for limited or no internal support to withstand positive internal pressure, and easy inspection of the internal surface for cracks or other defects.

[0054] the term The wording and terminology used in this document are for descriptive purposes and should not be considered restrictive.

[0055] The terms “approximately,” “approximately equal to,” and other similar phrases (e.g., “the value of X is approximately Y” or “X is approximately equal to Y”) used in the specification and claims should be understood to indicate that a value (X) is within a predetermined range of another value (Y). Unless otherwise stated, the predetermined range may be positive or negative 20%, 10%, 5%, 3%, 1%, 0.1%, or less than 0.1%.

[0056] The indefinite articles “a” and “an” used in the specification and claims, unless explicitly indicated to the contrary, should be understood to mean “at least one”. The phrase “and / or” used in the specification and claims should be understood to mean “any one or both” of the elements so combined, i.e., the elements are present in combination in some cases and separately in others. Multiple elements listed with “and / or” should be interpreted in the same way, i.e., “one or more” of the elements so combined. In addition to the elements specifically identified by the “and / or” clause, other elements may optionally be present, whether related to or unrelated to those specifically identified. Thus, as a non-limiting example, when used in conjunction with open-ended language such as “comprising”, a reference to “A and / or B” may in one embodiment refer only to A (optionally including elements other than B); in another embodiment, only to B (optionally including elements other than A); in yet another embodiment, both A and B (optionally including other elements); and so on.

[0057] As used in the specification and claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” should be interpreted as inclusive, meaning that it includes multiple elements or at least one but more than one element in the list, as well as optional unlisted items. Only terms that explicitly indicate the opposite, such as “only one of…” or “exact one of…”, or, when used in the claims, “consisting of…”, will refer to multiple elements or exactly one element in the list. Generally, the term “or” used should only be interpreted as indicating an exclusive alternative (i.e., “one or the other but not both”) when preceded by an exclusive term such as “any one,” “one of…,” “only one of…,” or “exact one of…”. “Substantially consisting of…” should have its ordinary meaning when used in the claims.

Claims

1. A buoyancy system for an underwater autonomous vehicle, the buoyancy system comprising: One or more spherical pressure vessels, each of the one or more spherical pressure vessels comprising two hemispherical members mechanically or adhesively joined together at a joint, wherein each of the one or more spherical pressure vessels comprises one or more bulkhead penetrations for connecting the one or more spherical pressure vessels to external components, valves and sensors of the buoyancy system; A seawater inlet valve, connected to at least one of the one or more spherical pressure vessels, for introducing seawater into the one or more spherical pressure vessels; A main pump connected to at least one of the one or more spherical pressure vessels, wherein the main pump is configured to pump seawater from the one or more spherical pressure vessels; A pressure sensor, the pressure sensor being connected to at least one of the one or more spherical pressure vessels; and A level sensor extending through all or a first subgroup of the one or more spherical pressure vessels, the level sensor being configured to detect the level of seawater inside the one or more spherical pressure vessels between a first limit and a second limit.

2. The buoyancy system according to claim 1, wherein, The first subgroups of the one or more spherical pressure vessels are stacked vertically on top of each other and interconnected via the liquid level sensor.

3. The buoyancy system according to claim 2, wherein, The second subgroup of the one or more spherical containers is positioned on the first side of the first subgroup.

4. The buoyancy system according to claim 3, wherein, The third subgroup of the one or more spherical descriptors is positioned on the second side of the first subgroup, opposite to the second subgroup.

5. The buoyancy system according to claim 4, wherein, Each of the second and third subgroups of the one or more spherical pressure vessels is connected to the topmost and bottommost spherical pressure vessel of the first subgroup.

6. The buoyancy system according to claim 1, wherein, The volume of seawater in each of the one or more spherical pressure vessels is independently controlled via the operation of the main pump.

7. The buoyancy system according to claim 1, wherein, The first limit represents the highest permissible seawater level, and the second limit represents the lowest permissible seawater level.

8. The buoyancy system according to claim 1, wherein, The one or more spherical pressure vessels contain a volume of seawater and a volume of gas.

9. The buoyancy system according to claim 8, wherein, The gas is at least one of air or filtered air.

10. The buoyancy system according to claim 1, wherein, The one or more spherical pressure vessels are configured to operate at ocean depths of approximately 5 km to 6 km.

11. The buoyancy system according to claim 1, wherein, The one or more spherical pressure vessels are configured to withstand an external pressure of approximately 600 bar.

12. A deep-sea mining system, the system comprising: A dynamic buoyancy system comprising one or more spherical pressure vessels, each of the one or more spherical pressure vessels comprising two hemispherical members mechanically or adhesively joined together at a joint, wherein each of the one or more spherical pressure vessels comprises one or more bulkhead penetrations for connecting the one or more spherical pressure vessels to external components, valves and sensors of the dynamic buoyancy system; Autonomous underwater vehicles; and Ore collection system; The dynamic buoyancy system is configured to dynamically control the buoyancy of the deep-sea mining system as it descends, ascends, and remains at a predetermined ocean depth during the ore collection process.

13. The system according to claim 12, wherein, The dynamic buoyancy system dynamically controls the buoyancy of the deep-sea mining system by independently adjusting the liquid volume in each of the one or more spherical pressure vessels.

14. The system according to claim 12, wherein, The predetermined ocean depth is between 5 km and 6 km.

15. The system according to claim 12, wherein, The dynamic buoyancy system is further configured to adjust the buoyancy of the deep-sea mining system by reducing the volume of liquid within the one or more spherical pressure vessels to compensate for weight changes in the deep-sea mining system during the ore collection process.

16. The system of claim 12, further comprising a level sensor extending through all spherical pressure vessels or a first subgroup of the one or more spherical pressure vessels, the level sensor being configured to detect the level of liquid inside the one or more spherical pressure vessels between a first limit and a second limit.

17. The system according to claim 16, wherein, The first subgroups of the one or more spherical pressure vessels are stacked vertically on top of each other and interconnected via the liquid level sensor.

18. The system according to claim 17, wherein, The second subgroup of the one or more spherical containers is positioned on the first side of the first subgroup.

19. The system according to claim 18, wherein, The third subgroup of the one or more spherical descriptors is positioned on the second side of the first subgroup, opposite to the second subgroup.

20. The system according to claim 19, wherein, Each of the second and third subgroups of the one or more spherical pressure vessels is connected to the topmost and bottommost spherical pressure vessel of the first subgroup.

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