Method and apparatus for dynamic buoyancy system for deep sea mining

Abstract

A buoyancy system for an autonomous underwater vehicle is provided. The buoyancy system includes one or more pressure vessels, a main pump connected to each of the one or more pressure vessels, wherein the main pump is configured to draw liquid from the one or more pressure vessels. The buoyancy system also includes a controller communicatively coupled to the main pump and configured to operate the main pump via wireless or wired communication, and a power source configured to provide power to the controller and the main pump.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 314,807, filed on February 28, 2022, entitled “METHOD AND APPARATUS FOR ADYNAMIC BUOYANCY SYSTEM FOR DEEP-SEA MINING,” which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates generally to deep sea mining systems, and more particularly to a dynamic buoyancy system implemented in a deep sea mining system that applies variable buoyancy conditions that allow the deep sea mining system to descend, collect ore nodules from the sea floor, and ascend without contacting the sea floor to limit environmental impact. Background Art

[0004] As the world shifts to green energy options, there is a growing demand for storing energy in reusable batteries made from key metals such as nickel, copper and cobalt. Currently, there are fewer sources of these metals remaining on land, and these land-based resources may be located in challenging locations and / or within sensitive ecosystems. Deep sea mining is an untapped source of key metals in the form of ore nodules (e.g., polymetallic ferromanganese nodules) and has become a focus of the mining industry in recent years.

[0005] Technical difficulties associated with deep sea mining include the ocean depths (e.g., 5 km to 6 km) and extreme pressures (e.g., between 500 bar and 600 bar) where ore nodule mining occurs, and the technology required to transport the mined ore up to the ocean surface. There are two systems that have been extensively tested and determined to be feasible on a small scale: (i) seabed dredge collector systems that pump the ore to the surface as a slurry through vertical risers, and (ii) mechanical lifting systems using synthetic ropes. However, both systems suffer from reliability and scaling issues, and can cause irreparable damage to sensitive environments due to disturbances caused on the seabed during the mining process.

[0006] Therefore, a more sustainable way of extracting minerals from the seafloor is needed while keeping the seabed ecosystem intact. Summary of the invention

[0007] A dynamic buoyancy system implemented for a deep-sea mining system and a method for using the dynamic buoyancy system are disclosed herein. According to some embodiments, the disclosed dynamic buoyancy system enables the deep-sea mining system to hover at a predetermined distance above the seabed during the entire mining process, which minimizes the environmental impact of the mining process. In addition, the deep-sea mining system using the dynamic buoyancy system disclosed herein does not rely on dredging or mud risers for ore collection and transportation to the sea surface, and can be expanded and deployed as a fleet of vehicles with redundancy. According to some embodiments, the dynamic buoyancy system enables the deep-sea mining system to descend to the seabed, navigate along the seabed without contact when collecting ore nodules, and rise to the surface to deliver its payload. The dynamic buoyancy system applies variable buoyancy technology and adopts a large pressure vessel, which is designed to work at the planned ocean depth without seabed contact and with minimal environmental damage when the deep-sea mining system descends, collects ore and rises. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The drawings, which are incorporated as a part of this specification, illustrate presently preferred embodiments, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain and teach the principles described herein.

[0009] Figure 1 An exemplary deep sea mining system is illustrated according to some embodiments.

[0010] Figure 2 A dynamic buoyancy system implemented in a deep sea mining system is illustrated according to some embodiments.

[0011] Figure 3 Operation of a dynamic buoyancy system implemented in a deep sea mining system is described according to some embodiments.

[0012] Figure 4 is an exemplary arrangement of a dynamic buoyancy system implemented in a deep sea mining system having a plurality of pressure vessels forming respective dynamic buoyancy subsystems, according to some embodiments.

[0013] Figure 5 is a top view of an array of dynamic buoyancy subsystems implemented in a deep sea mining system, according to some embodiments. DETAILED DESCRIPTION

[0014] Figure 1An exemplary deep sea mining system 100 is illustrated that is deployed from a mining vessel 110 to collect ore nodules 120 placed on the seabed according to some embodiments. The deep sea mining system 100 is lowered around the seabed and hovers above the seabed during the ore collection process. In some embodiments, the deep sea mining system 100 includes an underwater autonomous vehicle (UAV) 130, an ore collection system 140 that collects ore nodules 120 from the seabed, a payload hopper 150 for temporarily storing the collected ore, and a dynamic buoyancy system 160 that enables the deep sea mining system 100 to be maneuvered primarily in a vertical direction (e.g., to descend from the sea surface to the seabed and ascend from the seabed to the sea surface).

[0015] According to some embodiments, the UAV 130 is equipped with thrusters (not shown) that enable the deep sea mining system 100 to maneuver primarily in the lateral direction (e.g., parallel to the sea surface—along the xy plane) and secondarily in the vertical direction (e.g., along the z direction). Figure 1 ). By way of example and not limitation, the ore collection system 140 may be equipped with one or more robotic arms 140a that may extend toward the seabed and reach the ore nodules. In some embodiments, when the deep sea mining system 100 is hovering above the seabed, the robotic arms 140a may collect the ore nodules by picking them up and placing them into the payload hopper 130 via a conveyor belt, a suction system, or any other suitable means, method, or technique.

[0016] 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 sea floor and determine whether marine life is anchored to the nodules. By way of example and not limitation, the deep sea mining system 100 can be configured to avoid collecting ore nodules that have marine life anchored thereon. Once the payload hopper 150 is full, the dynamic buoyancy system 160 enables the deep sea mining system 100 to rise to the sea surface and deliver its payload.

[0017] According to some embodiments, the components of the deep sea mining system 100 (e.g., the dynamic buoyancy system 160, the payload hopper 150, the ore collection system 140, and the UAV 130) operate in coordination. In some embodiments, these components may be integrated into a housing or operated as detachable modules that are physically and communicatively connected to each other. According to some embodiments, the dynamic buoyancy system 160, the payload hopper 150, the ore collection system 140, and the UAV 130 are physically attached to each other during the collection / mining process, and at least the payload hopper 150 and the dynamic buoyancy system 160 are physically attached to each other during the mining and ascent process. In some embodiments, the dynamic buoyancy system 160 can provide the necessary buoyancy to compensate for the ore collected during the mining process and the ascent of at least the payload hopper 150 or the entire deep sea mining system 100. In some embodiments, if the dynamic buoyancy system 160 and payload hopper 150 rise to the ocean surface on their own, the UAV 130 can use its thrusters to provide the necessary buoyancy for the deep sea mining system 100 until the dynamic buoyancy system 160 and payload hopper 150 are lowered from the ocean surface again to be reattached to the deep sea mining system 100.

[0018] In some embodiments, the deep sea mining system 100 may include additional components, modules, and systems that are necessary for its operation. For simplicity, these additional components, modules, and systems are not shown in FIG. Figure 1 By way of example and not limitation, these additional components, modules, and systems may include cables, one or more onboard computers, electronic equipment, additional thrusters, motors, batteries, communications equipment, cameras, radars, controllers, global positioning systems, and the like. These additional components, modules, and systems are within the limits and scope of the present disclosure. In some embodiments, the deep-sea mining system 100 may operate in an autonomous mode, a semi-autonomous mode, a manual mode, or a combination thereof based on instructions from the mining vessel 110. In yet another embodiment, the deep-sea mining system 100 may be communicatively coupled and physically connected to the mining vessel 110 via ropes, cables, and the like.

[0019] According to some embodiments, details of the dynamic buoyancy system 160 are shown in Figure 2 In. As in Figure 2As shown in , the dynamic buoyancy system 160 includes a pressure vessel 200, a buoyancy foam 210, a main pump 220, a controller 230 capable of receiving and transmitting data, and a power supply 240 with a charging port 240a. According to some embodiments, all components in the dynamic buoyancy system 160 are designed to operate at an ocean depth between about 5km and 6km. However, this is not restrictive, and the dynamic buoyancy system 160 can be configured to operate at a greater or lesser depth. In some embodiments, the pressure vessel volume (volume, capacity) can be selected based on the mineral payload weight target. For example, a larger payload weight requires a higher pressure vessel volume than a smaller payload weight.

[0020] As in Figure 2 As shown in FIG. 1 , the pressure vessel 200 contains a compressible gas (e.g., air, filtered air, or another suitable gas or gas mixture) and an incompressible liquid (e.g., seawater, filtered seawater, desalinated water, deionized water, or another suitable liquid) in gray shades. In some embodiments, the dynamic buoyancy system 160 may include one or more secondary pumps in addition to the primary pump 220. For example, an optional gas pump 250 for gas pressurization may be attached to the valve 260 to pre-fill the pressure vessel 200 with compressible gas at the sea surface. According to some embodiments, the valve 260 may allow gas to enter the pressure vessel 200 and prevent liquid and gas from escaping the pressure vessel 200. In addition, the valve 260 may prevent seawater from entering the pressure vessel 200 when the dynamic buoyancy system 160 is located at a mining depth (e.g., located at a depth between 5 km and 6 km). As used herein, the term "optional" means that the gas pump 250 may or may not be attached to the pressure vessel 200 (e.g., via the valve 260) at all times. For example, the gas pump 250 may be located on the mining vessel 110 and may be connected to the pressure vessel 200 via the valve 260 when the buoyancy system 160 is at the sea surface, and then disconnected from the pressure vessel 200 when the buoyancy system 160 is ready to descend. In another embodiment, the gas pump 250 may remain attached to the pressure vessel 200 via the valve 260 during the descent and mining process (e.g., at all times). In some embodiments, a low pressure subsea liquid pump 270 may be attached to the valve 280 to pump an incompressible liquid into the pressure vessel 200 at the sea surface. In some embodiments, the subsea liquid pump 270 may introduce liquid into the pressure vessel 200 during descent or during the mining process, as later described in conjunction with the subsea liquid pump 270. Figure 3 By way of example and not limitation, the subsea liquid pump 270 can provide gas at a pressure of approximately 200 psi. Additionally, the subsea liquid pump 270 can be uninsulated and can be allowed to dissipate heat generated via its operation into the ocean.

[0021] In some embodiments, the main pump 220 is a high pressure low volume (HPLV) pump for extracting incompressible liquid from the pressure vessel 200 (e.g., via valve 290) at a depth corresponding to an ambient seawater pressure of about 600 bar. In some embodiments, the main pump 220 can be a high power output pump (e.g., having an output power of about 300 hp) with a pumping speed that can match the ore collection rate. By way of example and not limitation, the pumping speed of the main pump 220 can be at least 4 liters / second. By way of example and not limitation, the main pump 220 can be a single-stage or multi-stage pump.

[0022] When the dynamic buoyancy system 160 is at the sea surface, the pump described above can be powered by a rechargeable power source 240, which can be charged via a charging port 240a. According to one embodiment, the power source 240 can be a 400kWh rechargeable battery. By way of example and not limitation, the power source 240 can be a lithium iron phosphate (LiFePO4) battery. However, any suitable rechargeable battery can be used based on the desired cycle durability and energy density requirements.

[0023] According to some embodiments, Figure 1 The deep sea mining system 100 shown in FIG. 1 can estimate its ore collection rate by measuring, for example, the mass of ore collected in the payload hopper 150 via its instrumentation. In response, the dynamic buoyancy system 160 can use the collection rate estimate to adjust the buoyancy of the deep sea mining system 100. At the same time, and if necessary, the UAV 130 can activate its thrusters to keep the deep sea mining system 100 within an operating distance from the seafloor (e.g., within the reach 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 so that the dynamic buoyancy system 160 can adjust the buoyancy of the deep sea mining system 100 to reduce the total vertical thrust compensation from the UAV 130.

[0024] refer to Figure 2 , the controller 230 may be configured to receive instrument readings of the deep sea mining system 100 - such as pressure readings, temperature readings, volume readings, mass readings, acquisition rates and other types of rates, etc. The controller 230 may also be configured to receive / transmit data within, 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 other embodiments, the controller 230 may include standard processing equipment, such as a single board computer like a Raspberry Pi or an ARM processor.

[0025] According to some embodiments, the dynamic buoyancy system 160 is further equipped with sensors (not shown). Figure 2 ), to constantly monitor the pressure inside the pressure vessel 200, the flow rate of the liquid through the pipeline, the temperature of the controller 230, the temperature of the pumps (e.g., the gas pump 250 and the subsea liquid pump 270), and the temperature of the power supply 240.

[0026] In some embodiments, the buoyancy foam 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., at a depth between about 5 km and 6 km), the dynamic buoyancy system 160 itself is neutrally buoyant. By way of example and not limitation, the buoyancy foam 210 can be a synthetic foam, such as resin cast hollow glass microspheres (microballoons). Adding the buoyancy foam to the dynamic buoyancy system 160 increases buoyancy. Neutral buoyancy can be achieved by adding enough buoyancy foam 210 so that the upward force due to water displacement caused by the buoyancy foam 210 and the pressure vessel 200 compensates for the mass of the dynamic buoyancy system 160.

[0027] In other embodiments, the deep sea mining system 100 may include a buoyancy system featuring more than one (e.g., multiple) pressure vessels 200, such as in Figure 4 The invention is shown by way of example and not limitation. Figure 4 In an exemplary configuration, the pressure vessels 200 may be connected to a single pump 220 and controller 230 pair via a central manifold 400. In addition, 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 4 In the diagram, the gas pump 250, the subsea liquid pump and the buoyancy foam 210 are omitted for simplicity. 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.

[0028] By way of example, the deep sea mining system 100 may be equipped with a buoyancy system having an array of 21 pressure vessels 200, each pressure vessel 200 forming a buoyancy system as in Figure 5 The dynamic buoyancy subsystem 400 is arranged in a 3×7 array as shown in Figure 1 A top view of the deep sea mining system 100 along line AB is shown in FIG. In some embodiments, Figure 4 and Figure 5Each dynamic buoyancy subsystem 400 in the deep sea mining system 100 can be independently controlled via its valves 260, 280 and 290. It should be understood that fewer or additional buoyancy systems 400 (e.g., fewer or more than 21) can be used in any suitable configuration, depending on the size of the deep sea mining system 100 and the payload weight that the deep sea mining system 100 needs to carry. That is, Figure 4 and Figure 5 The configuration shown in is non-limiting and provides only one of many possible embodiments and configurations. Figure 4 and Figure 5 Additional configurations and arrangements beyond those shown in the drawings are possible and are within the spirit and scope of the present disclosure.

[0029] Using multiple dynamic buoyancy systems, as discussed above, the deep sea mining system 100 can compensate for an uneven distribution of ore nodules in the payload hopper 150. For example, an uneven loading may occur when the ore nodules are not evenly 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 an uneven loading scenario, the thrusters of the UAV 130 on the heavy side will have to continue to operate to keep the deep sea mining system 100 level. In contrast, and by using an array of dynamic buoyancy systems (e.g., an array of dynamic buoyancy systems 400 as discussed above), the buoyancy can be adjusted by operating the dynamic buoyancy system 400 on the heavy side so that the deep sea mining system 100 remains level without corrective action from the thrusters of the UAV 130.

[0030] Another benefit of using multiple dynamic buoyancy systems is operational redundancy. For example, in the event that one of the dynamic buoyancy systems fails, another dynamic buoyancy system can be activated so that the deep sea mining system 100 can continue to operate without interruption.

[0031] According to some embodiments, the dynamic buoyancy system (e.g., each of the dynamic buoyancy system 160 or the dynamic buoyancy system 400) responds to data communications from other modules and dynamically adjusts buoyancy by pumping liquid into and out of its pressure vessel 200 to meet the motion objectives of the deep sea mining system 100. According to some embodiments, the dynamic buoyancy system can communicate with the UAV 130, which can request buoyancy rate adjustments based on thrust vectoring requirements so that the deep sea mining system 100 maintains its distance from the seabed. As used herein, the term "thrust vector" refers to the combined forces acting on the deep sea mining system 100 at any given moment, and includes the vertical buoyancy forces applied by one or more dynamic buoyancy systems and the horizontal and / or vertical forces applied by the thrusters of the UAV 130. Additionally, the dynamic buoyancy system may communicate with the ore collection system 140, which based on its sensed ore mass collection rate may request that the buoyancy be adjusted to maintain the deep sea mining system 100 at a predetermined distance from the sea floor without engaging the thrusters from the UAV 130. This limits the energy consumed by the UAV 130. Furthermore, the dynamic buoyancy system may communicate with the mining vessel 110 (e.g., via the UAV 130 or via another module) to adjust the buoyancy so that the deep sea mining system 100 can be parked at a given depth in the event of adverse weather, maintenance, and other reasons.

[0032] According to some embodiments, the operation of dynamic buoyancy system 160 (and each of dynamic buoyancy systems 400) under different buoyancy conditions is Figure 3 More specifically, Figure 3 Demonstrates how the level of liquid (grey shading) in the pressure vessel 200 can be adjusted by the dynamic buoyancy system 160 to Figure 1 The deep sea mining system 100 shown in FIG. 1 achieves different buoyancy conditions.

[0033] According to some embodiments, the gas pressure inside the pressure vessel 200 must be sufficient so that when the entire volume of liquid from the pressure vessel 200 is extracted, the gas pressure inside the pressure vessel 200 is equal to or slightly below atmospheric pressure (i.e., between about 14.6 psi and about 3.2 psi, where 14.6 psi is atmospheric pressure) so that the main pump 220 can remain operational underwater. In the event that the gas pressure inside the pressure vessel 200 is insufficient and the pressure vessel 200 is "under vacuum" (e.g., the pressure of the pressure vessel 200 is below 3.2 psi) while liquid is still being extracted, the remaining liquid will begin to evaporate, and the vapor pressure of the liquid may impair the ability of the pump to remove additional liquid from the pressure vessel 200. In this "pressure vessel vacuum scenario," the dynamic buoyancy system 160 will not be able to provide the necessary buoyancy for the deep sea mining system 100.

[0034] The above-described "pressure vessel vacuum scenario" can be avoided by setting the initial volume and pressure of the gas in the pressure vessel 200 so that when all the desired liquid is extracted, the pressure of the gas (as approximately estimated by the ideal gas law) is no less than the extractable limit of the main pump 220 (e.g., less than about 3.2 psi). The gas pressure (together with the maximum internal operating pressure of the pressure vessel 200) can determine the minimum volume of gas allowed in the pressure vessel 200 and therefore the maximum volume of liquid. Additional gas volume can be allocated (e.g., a larger pressure vessel 200 can be used) to reduce the gas pressure in the pressure vessel 200 and increase the maximum allowable liquid volume so that when the pressure vessel 200 is emptied of liquid, the gas pressure is equal to or above the minimum extractable limit of 3.2 psi - for example, between about 14.6 psi and about 3.2 psi, as described above. Alternatively, additional static buoyancy can be provided by increasing the amount of buoyancy foam 210 in the dynamic buoyancy system 160.

[0035] In some embodiments, and when the buoyancy of the deep sea mining system 100 is on the surface, the pressure vessel 200 may be prepared to have an air volume that includes: (i) a minimum gas volume 300, (ii) a static buoyancy gas volume 310, and (iii) a gas volume reserved for a descending mass volume 320, as in Figure 3 . According to some embodiments, the minimum gas volume 300 prevents the "pressure vessel vacuum scenario" discussed above. The static buoyancy gas volume 310 is the additional gas volume that is never displaced by the 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 displaced by the liquid. As shown in FIG. Figure 2As discussed, gas may be pumped into the pressure vessel 200 using the gas pump 250 via the valve 260. At this point, the deep sea mining system 100 has positive buoyancy and last minute testing may occur.

[0036] According to some embodiments, the dynamic buoyancy system 160 is designed so that if the volume of liquid present in the pressure vessel 200 is equal to the neutral buoyancy level, the deep sea mining system 100 can be neutrally buoyant. Figure 3 In the embodiment of FIG. 3 , the neutral buoyancy level is represented by dashed line 300. In a “pre-descent” stage A, as shown in FIG. 3 , the volume of liquid in pressure vessel 200 is less than the neutral buoyancy level 300 and the ‘descent mass’ volume 320 (e.g., the volume occupied by the ‘descent mass’ of liquid). Pre-descent stage A represents a situation where deep sea mining system 100 is at the sea surface and has positive buoyancy.

[0037] When starting to descend (for example, by Figure 2 ), a body of liquid equal to the descending mass volume 320 is pumped into the pressure vessel 200, as in Figure 3 The additional liquid volume, according to some embodiments, renders the deep sea mining system 100 negatively buoyant. As a result, a net downward force acts on the deep sea mining system 100 and accelerates it to its terminal downward velocity within the water. According to some embodiments, the liquid is used Figure 2 The subsea liquid pump 270 shown in FIG. 2 is pumped into the deep sea mining system 100 via valve 280. The final speed of the deep sea mining system 100 can be further controlled by controlling the volume of liquid in the pressure vessel 200. For example, to reduce the final speed, the liquid volume can be gradually increased from Figure 3 The upper descending mass volume restriction 340 in the middle is reduced without reaching the neutral buoyancy level 300. As described above in conjunction with Figure 2 As discussed, liquid may be pumped via valve 290 using main pump 220 .

[0038] As the deep sea mining system 100 approaches the sea floor, it is commanded to pump out enough liquid volume to achieve neutral buoyancy, which removes the downward force and causes it to slow down and stop close to the sea floor. In other words, when the deep sea mining system 100 reaches its target depth (e.g., between 5 km and 6 km), the main pump 220 can bring the volume of liquid to a neutral buoyancy level 300, causing the deep sea mining system 100 to become neutrally buoyant. This ensures that the deep sea mining system 100 can stay at its target depth (e.g., at a predetermined distance from the sea floor) using minimal effort and without relying heavily on thrusters from the UAV 130. According to some embodiments, Figure 1 The thrusters of the UAV 130 shown in FIG. 1 can be used only for fine depth adjustments. This buoyancy condition is shown in FIG. 1 through the "deceleration / neutral / start acquisition" C stage. Figure 3 middle.

[0039] 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 (e.g., along the Figure 1 ) and occasionally navigates vertically (e.g., in the z direction) when necessary to follow the contours of the seafloor. As the deep sea mining system 100 collects ore nodules 120 from the seafloor and gains weight, neutral buoyancy is maintained by pumping out additional volumes of liquid to compensate for the added weight of the ore, as in Figure 3 , as shown in the "Collect / Complete / Neutral" stage D of the deep sea mining system 100. According to some embodiments, the buoyancy required 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 liquid extracted should follow the total (net water) mass of the ore nodules collected. Because the ore has less weight in the water due to its buoyancy, the net water mass is the reduced mass since it displaces the water, which will produce a downward force observed and measured by the systems of the deep sea mining system 100. The amount of buoyancy required can be communicated to the dynamic buoyancy system 160, which can extract liquid at a dynamically varying rate. As shown in Figure 3 As shown in FIG, most of the volume of the liquid in the pressure vessel 200 is used to compensate for the maximum ore mass loaded while the deep sea mining system 100 remains neutrally buoyant.

[0040] According to some embodiments, the extraction rate of the liquid (which is based on the known density of the liquid) is proportional to the extraction rate of the pump (which is proportional to the rotation rate of the pump) and is matched to the collected (net water) ore mass loading rate. In some embodiments, the mass loading rate is given by Figure 1. By way of example and not limitation, the ore collection system 140 may estimate the mass loading rate based on: (i) visual cues from an onboard camera (e.g., using an implementation of computer vision), (ii) electrical power measurements from a conveyor that can track the mass of the collected ore, or (iii) other suitable volume or mass measurement instrumentation (e.g., a deflection sensor) configured to provide a mass estimate.

[0041] According to some embodiments, any difference between the estimated and actual ore mass will result in a buoyancy error, which can be immediately compensated by the thrusters of the UAV 130. As discussed above, the operation of the thrusters in 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 remains neutrally buoyant during the collection process and when the collection process is completed.

[0042] Once the deep sea mining system 100 reaches its maximum loading capacity and it is time for it to ascend, the dynamic buoyancy system 160 is requested (e.g., via data communication with the controller 230) to pump out (e.g., using the main pump 220) a volume of liquid equal to the ascending mass volume 350. This allows the deep sea mining system 100 to achieve positive buoyancy and ascend with the ore payload at a terminal velocity towards the sea surface. This is accomplished by Figure 3 The "up" phase E in FIG. 2 is schematically shown. According to some embodiments, a retention mass volume of liquid is available to ensure that the main pump 220 operates as expected and to balance the ore load if necessary. The retention volume of liquid is Figure 3 Shown in FIG. 3 is an additional mass volume 360 ​​.

[0043] In some embodiments, when it is desired to temporarily "park" the deep sea mining system 100 during an ascent or descent without long term energy use, data communications to the controller 230 may command the dynamic buoyancy system 160 to pump in or out of liquid (whatever the case may be) to achieve neutral buoyancy. The process may be reversed when travel is resumed.

[0044] It should be understood that the dynamic buoyancy system described herein is not limited to deep sea mining systems and can be implemented in any type of submerged vehicle operating under autonomous control, semi-autonomous control or manual control at any operating depth. In addition, the dynamic buoyancy system described herein is not limited to submerged vehicles carrying a payload.

[0045] The operating principles for the dynamic buoyancy system 160 described herein are directly applicable to deep sea mining systems equipped with a plurality of pressure vessels 200, such as in Figure 4 and Figure 5In 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 3×7 arrangement, the 21 dynamic buoyancy systems can be divided into three subgroups (e.g., one 3×2 subgroup, one 3×3 subgroup, and another 3×2 subgroup), where each subgroup operates independently of the other subgroups. These and other similar variations and arrangements are within the spirit and scope of the present disclosure.

[0046] the term

[0047] The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0048] As used in the specification and claims, the term "approximately", the phrase "approximately equal to" and other similar phrases (e.g., "X has a value of approximately Y" or "X is approximately equal to Y"), should be understood to mean that one value (X) is within a predetermined range of another value (Y). Unless otherwise indicated, the predetermined range may be plus or minus 20%, 10%, 5%, 3%, 1%, 0.1%, or less than 0.1%.

[0049] As used in the specification and claims, the indefinite articles "a" and "an" should be understood to mean "at least one" unless clearly indicated to the contrary. As used in the specification and claims, the phrase "and / or" should be understood to mean "any one or two" of the elements so combined (i.e., elements shown in combination in some cases and separately in other cases). Multiple elements listed with "and / or" should be interpreted in the same manner, i.e., "one or more" of the elements so combined. Other elements other than those specifically identified by the "and / or" clause may optionally be present, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, reference to "A and / or B", when used in conjunction with open language such as "comprising", may refer to only A (optionally including elements other than B) in one embodiment; to only B (optionally including elements other than A) in another embodiment; to both A and B (optionally including other elements) in yet another embodiment; etc.

[0050] As used in the specification and claims, "or" should be understood to have the same meaning as "and / or" defined above. For example, when separating the items in a list, "or" or "and / or" should be understood to be inclusive, i.e., including at least one of some or a list of elements, but also including more than one, and optionally, additional items not in the list. Only terms that clearly indicate the opposite, such as "only one of..." or "exactly one of...", or, when used in the claims, "consisting of..." will refer to including exactly one element of some or a list of elements. Generally, when there are exclusive terms in front, such as "any one", "one of...", "only one of..." or "exactly one of...", the term "or" as used should only be interpreted as indicating exclusive alternatives (i.e., "one or the other, not both"). When "essentially consisting of..." is used in the claims, it should have its usual meaning as used in the field of patent law.

[0051] As used in the specification and claims, referring to a list of one or more elements, the phrase "at least one" should be understood to mean at least one element selected from any one or more elements in the list of elements, but does not necessarily include at least one of each element specifically listed within the list of elements, and does not exclude any combination of elements in the list of elements. This limitation also allows that in addition to the elements specifically identified in the list of elements referred to by the phrase "at least one", elements may optionally be present, whether related or unrelated to those specifically identified elements. Thus, as a non-limiting example, in one embodiment, "at least one of A and B" (or, equivalently, "at least one of A or B", or, equivalently, "at least one of A and / or B") may refer to at least one, optionally including more than one A, in which B is absent (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one B, in which A is absent (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one A and at least one, optionally including more than one B (and optionally including other elements), etc.

[0052] The use of "including," "comprising," "having," "containing," "involving," and variations thereof, is meant to encompass the items listed thereafter as well as additional items.

[0053] The use of ordinal terms such as "first", "second", "third", etc. in the claims to modify claim elements themselves does not imply any priority, precedence, or order of one claim element over another, or the temporal order in which method acts are performed. Ordinal terms are used only as labels to distinguish one claim element having a certain name from another element having the same name (but for the purpose of use of the ordinal terms) to distinguish claim elements.

[0054] Having thus described several aspects of at least one embodiment of the present invention, it will be appreciated that various changes, modifications and improvements will readily occur to those skilled in the art. Such changes, modifications and improvements are intended to be a part of this disclosure and are intended to fall within the spirit and scope of the present invention. Therefore, the foregoing description and accompanying drawings are provided by way of example only.

Claims

1. A buoyancy system for an underwater autonomous vehicle, the buoyancy system comprising: one or more pressure vessels; a main pump connected to each of the one or more pressure vessels, wherein the main pump is configured to draw liquid from the one or more pressure vessels; a controller communicatively coupled to the master pump and configured to operate the master pump via wireless or wired communication; as well as A power supply is configured to provide power to the controller and the main pump.

2. The buoyancy system of claim 1 , further comprising: a first pump connected to each of the one or more pressure vessels via a liquid inlet valve, the first pump being configured to pump liquid into each of the one or more pressure vessels when commanded by the controller; as well as A second pump is connected to each of the one or more pressure vessels via an inlet valve, the second pump being configured to pump gas into each of the one or more pressure vessels when commanded by the controller.

3. The buoyancy system of claim 1 wherein the volume of liquid within each of the one or more pressure vessels is independently controlled by the controller via operation of the main pump.

4. The buoyancy system of claim 1 wherein the one or more pressure vessels are arranged in an array.

5. The buoyancy system of claim 1 wherein the one or more containers contain a liquid volume and a gas volume.

6. The buoyancy system of claim 5 wherein the liquid is at least one of seawater, filtered seawater, desalinated water or deionized water.

7. The buoyancy system of claim 5 wherein the gas is at least one of air or filtered air.

8. The buoyancy system of claim 1 wherein the pressure of the gas contained in each of the one or more pressure vessels is between about 14.1 psi and about 3.2 psi.

9. The buoyancy system of claim 1 wherein the power source is a battery pack.

10. The buoyancy system of claim 1 wherein the buoyancy system is configured to operate at ocean depths up to approximately 5 km to 6 km.

11. A deep sea mining system, the system comprising: a dynamic buoyancy system comprising one or more pressure vessels; Autonomous underwater vehicles; as well as Ore collection systems; Wherein the dynamic buoyancy system is configured to dynamically control the buoyancy of the deep sea mining system as the deep sea mining system descends, ascends and remains at a predetermined ocean depth during an ore recovery process.

12. The system of claim 11, wherein the dynamic buoyancy system dynamically controls the buoyancy of the deep sea mining system by independently adjusting the volume of liquid within each of the one or more pressure vessels.

13. The system of claim 12, wherein each of the one or more pressure vessels of the dynamic buoyancy system contains a gas having a pressure between about 14.6 psi and about 3.2 psi.

14. The system of claim 11, wherein the predetermined ocean depth is between 5 km and 6 km.

15. The system of claim 11, wherein the dynamic buoyancy system is further configured to adjust the buoyancy of the deep sea mining system to compensate for changes in weight of the deep sea mining system caused during the ore collection process.

16. The system of claim 11, wherein the dynamic buoyancy system is further configured to maintain the deep sea mining system neutrally buoyant throughout the ore recovery process.

17. The system of claim 11, wherein the dynamic buoyancy system further comprises: a main pump connected to each of the one or more pressure vessels, wherein the main pump is configured to draw liquid from the one or more pressure vessels; a controller communicatively coupled to the master pump and configured to operate the master pump via wireless or wired communication; as well as A power supply is configured to provide power to the controller and the main pump.

18. The system of claim 17, wherein the liquid is at least one of seawater, filtered seawater, desalinated water, or deionized water.

19. The system of claim 17, wherein the dynamic buoyancy system further comprises: a first pump connected to each of the one or more pressure vessels via a liquid inlet valve, the first pump being configured to pump liquid into each of the one or more pressure vessels when commanded by the controller; as well as A second pump is connected to each of the one or more pressure vessels via an inlet valve, the second pump being configured to pump gas to each of the one or more pressure vessels when commanded by the controller.

20. The system of claim 19, wherein the gas is at least one of air or filtered air.

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