Patent application title: SYSTEMS AND METHODS FOR REMOTE BUOYANCY CONTROL
Inventors:
Shelby Kathleen Andersson (Boca Raton, FL, US)
IPC8 Class: AB63G824FI
USPC Class:
701 21
Class name: Data processing: vehicles, navigation, and relative location vehicle control, guidance, operation, or indication marine vehicle
Publication date: 2016-04-21
Patent application number: 20160107736
Abstract:
A system for controlling the buoyancy of a remotely operated vehicle. The
system includes buoyancy tanks, storage tanks, pressure sensors,
gyroscopes, a control unit, and transporting and conducting means to
couple all the elements. The system autonomously adjusts the depth of all
or part of the remotely operated vehicle based at least in part on the
pressure readings and the orientation of the remotely operated vehicle.
The system is designed to reach the depths of the ocean floor either by a
high pressure encasement, or by adjusting the internal pressure of the
buoyancy tanks to withstand the ambient pressure exerted by the column of
water. The system is entirely closed, meaning that the buoyancy can be
adjusted simply by moving gas between a storage tank to a buoyancy tank.
The system can finely control total depth, roll, pitch, and yaw of the
remotely operated vehicle.Claims:
1. A buoyancy control system comprising: at least one buoyancy tank; at
least one pressurized storage tank coupled with the at least one buoyancy
tank; and at least one control arrangement, the at least one control
arrangement coupled with the at least one pressurized storage tank.
2. The buoyancy control system of claim 1, wherein the system forms a closed loop such that no gas is released.
3. The buoyancy control system of claim 1, wherein the at least one control arrangement comprises: at least one pressure sensor; and circuitry for determining a pressure at least partially based on a reading of the at least one pressure sensor.
4. The buoyancy control system of claim 2, wherein the at least one control arrangement comprises: at least a first pressure sensor; at least a second pressure sensor; and circuitry for comparing a pressure reading from the first pressure sensor against a pressure reading from the second pressure sensor.
5. The buoyancy control system of claim 1, wherein the at least one control arrangement comprises: at least one gyroscope; and circuitry for determining an orientation at least partially based on a reading of the at least one gyroscope.
6. The buoyancy control system of claim 1, wherein the at least one control arrangement comprises: at least one pressure sensor; circuitry for determining a pressure at least partially based on a reading of the at least one pressure sensor; at least one gyroscope; circuitry for determining an orientation at least partially based on a reading of the at least one gyroscope; and circuitry for adjusting a flow of a gas at least partially based on a pressure and the orientation of the buoyancy control system.
7. The buoyancy control system of claim 1, wherein the at least one control arrangement comprises: at least a first pressure sensor, the first pressure sensor situated to measure an external pressure; at least a second pressure sensor, the second pressure sensor situated to measure an internal pressure; circuitry for determining a comparative pressure between the first pressure sensor and the second pressure sensor; and circuitry for adjusting the internal pressure based on the comparative pressure determination.
8. The buoyancy control system of claim 1, wherein the at least one control arrangement comprises: at least a first pressure sensor; at least a second pressure sensor; circuitry for determining a comparative pressure between the first pressure sensor and the second pressure sensor; at least one gyroscope; circuitry for determining an orientation at least partially based on a reading of the at least one gyroscope; and circuitry for adjusting a flow of a gas at least partially based on the comparative pressure and the orientation of the buoyancy control system.
9. The buoyancy control system of claim 1, wherein the at least one control arrangement comprises: at least a first pressure sensor; at least a second pressure sensor; circuitry for determining a comparative pressure between the first pressure sensor and the second pressure sensor; at least one gyroscope; circuitry for determining an orientation at least partially based on a reading of the at least one gyroscope; and circuitry for adjusting a flow of a gas at least partially based on the comparative pressure and the orientation of the buoyancy control system, wherein the adjusting the flow of the gas alters the volume of gas in the at least one buoyancy tank.
10. A buoyancy control system comprising: a plurality of buoyancy tanks; at least one pressurized storage tank coupled with the plurality of buoyancy tanks; and at least one control arrangement, the at least one control arrangement coupled with the at least one pressurized storage tank.
11. The buoyancy control system of claim 10, wherein the system forms a closed loop such that no gases are released.
12. The buoyancy control system of claim 10, wherein the at least one control arrangement comprises: at least one pressure sensor; and circuitry for determining a pressure at least partially based on a reading of the at least one pressure sensor.
13. The buoyancy control system of claim 10, wherein the at least one control arrangement comprises: at least a first pressure sensor; at least a second pressure sensor; and circuitry for comparing a pressure reading from the first pressure sensor against a pressure reading from the second pressure sensor.
14. The buoyancy control system of claim 10, wherein the at least one control arrangement comprises: at least one gyroscope; and circuitry for determining an orientation at least partially based on a reading of the at least one gyroscope.
15. The buoyancy control system of claim 10, wherein the at least one control arrangement comprises: at least one pressure sensor; circuitry for determining a pressure at least partially based on a reading of the at least one pressure sensor; at least one gyroscope; circuitry for determining an orientation at least partially based on a reading of the at least one gyroscope; and circuitry for adjusting a flow of a gas at least partially based on a pressure and the orientation of the buoyancy control system.
16. The buoyancy control system of claim 10, wherein the at least one control arrangement comprises: at least a first pressure sensor, the first pressure sensor situated to measure an external pressure; at least a second pressure sensor, the second pressure sensor situated to measure an internal pressure; circuitry for determining a comparative pressure between the first pressure sensor and the second pressure sensor; and circuitry for adjusting the internal pressure based on the comparative pressure determination.
17. The buoyancy control system of claim 10, wherein the at least one control arrangement comprises: at least a first pressure sensor; at least a second pressure sensor; circuitry for determining a comparative pressure between the first pressure sensor and the second pressure sensor; at least one gyroscope; circuitry for determining an orientation at least partially based on a reading of the at least one gyroscope; and circuitry for adjusting a flow of a gas at least partially based on the comparative pressure and the orientation of the buoyancy control system.
18. The buoyancy control system of claim 10, wherein the at least one control arrangement comprises: at least a first pressure sensor; at least a second pressure sensor; circuitry for determining a comparative pressure between the first pressure sensor and the second pressure sensor; at least one gyroscope; circuitry for determining an orientation at least partially based on a reading of the at least one gyroscope; and circuitry for adjusting a flow of a gas at least partially based on the comparative pressure and the orientation of the buoyancy control system, wherein the adjusting the flow of the gas alters the volume of gas in the plurality of buoyancy tanks.
19. A buoyancy control system comprising: a plurality of buoyancy tanks; at least one pressurized storage tank coupled with the plurality of buoyancy tanks; and at least one control arrangement coupled with the at least one pressurized storage tank, the at least one control arrangement comprising: at least a first pressure sensor; at least a second pressure sensor; circuitry for determining a comparative pressure between the first pressure sensor and the second pressure sensor; at least one gyroscope; circuitry for determining an orientation at least partially based on a reading of the at least one gyroscope; and circuitry for adjusting a flow of a gas at least partially based on the comparative pressure and the orientation of the buoyancy control system, wherein the adjusting the flow of the gas alters the volume of gas in the plurality of buoyancy tanks.
Description:
FIELD OF THE INVENTION
[0001] This invention relates generally to buoyancy control, and, more specifically, to systems and methods for remote buoyancy control.
BACKGROUND OF THE INVENTION
[0002] Remotely operated vehicles are often used to conduct activities at great depths, such as on the ocean floor. The environment on the ocean floor is includes darkness, extreme high and low temperatures, and extremely high pressures. It is necessary to control the buoyancy of these remotely operated vehicles so that they do not merely drop to the ocean floor and can instead be used to conduct maneuvers, such as picking up or moving objects. The most commonly used current technology for adjusting buoyancy of these remotely operated vehicles consists of foam blocks, which allow only a particular depth to be reached and maintained, and which often break under the pressure of the water column above the remotely operated vehicle. Moreover, these foam blocks only allow for the rough adjustment up or down of the remotely operated vehicle. Another technology in less common use is the replacement of gas canisters on the remotely operated vehicle. When the remotely operated vehicle needs to descend, it releases gases from its buoyancy chambers and begins to fall. When it needs to ascend, the remotely operated vehicle must acquire new gas, a task which is difficult at depth. This requires the pre-placement of gas canisters on the ocean floor, or requires a tether to the surface for gas to be flowed to the remotely operated vehicle, both of which are inefficient and expensive operations. In the present invention, the needs for foam blocks, replacement canisters, and tethers are obviated.
SUMMARY
[0003] The present invention is an autonomous, closed-loop system that stores and releases gases to adjust the buoyancy of the remotely operated vehicle, eliminating the waste found in existing systems. Furthermore, the present invention allows the remotely operated vehicle to make more precise movements than existing systems allow. The system is set up such that fine alterations of gas volumes in a closed-loop system may be autonomously controlled, moving the same gas from storage tanks to buoyancy tanks and back, providing an autonomous buoyancy control system that can change the depth, roll, pitch, and yaw of the remotely operated vehicle. Moreover, the system autonomously adjusts the pressure of the buoyancy tanks to be within a pre-designated ratio to the ambient pressure, up to the pressure at the ocean floor, which is approximately 16,000 pounds per square inch. This allows the system to be open to the environment, partially accounting for the fine movements and adjustments facilitated by the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Embodiments of the present invention are described in detail below with reference to the following drawings:
[0005] FIG. 1 is a representative view of an exemplary arrangement of the buoyancy control system.
[0006] FIG. 2 is an example of a control arrangement.
DETAILED DESCRIPTION
[0007] The buoyancy control system provides a system for precisely controlling the depth, roll, pitch, and yaw of remotely operated vehicles. The buoyancy control system consists essentially of at least one buoyancy tank, at least one pressurized storage tank coupled with the at least one buoyancy tank, and at least one control arrangement, the at least one control arrangement coupled with the at least one pressurized storage tank. In the present embodiment, the system forms a closed loop such that no gases are released.
[0008] FIG. 1 shows the buoyancy control system, 1, on top of and coupled with the remotely operated vehicle, 2. The buoyancy control system is a means for controlling any of the depth, roll, pitch, or yaw of a remotely operated vehicle. In the present embodiment, the buoyancy control system is attachable to existing remotely operated vehicles. This is an exemplary embodiment, and it should not be construed as limiting. In other embodiments, the buoyancy control system is built into the remotely operated vehicle. In other embodiments, the buoyancy control system is attached to the bottom of the remotely operated vehicle. In other embodiments, the buoyancy control system is attached to the remotely operated vehicle in combination with other buoyancy control systems. In other embodiments, the buoyancy control system is attached to a side of the remotely operated vehicle.
[0009] The buoyancy control system is comprised essentially of a buoyancy tank, 3. In one embodiment, the buoyancy tank is a means for increasing the volume of gas in the buoyancy control system, which results in increased buoyancy. In another embodiment, it is a means for changing the location of a gas. In yet another embodiment, it is a means for changing the volume of a gas in a discrete location of the buoyancy control system. FIG. 1 shows an embodiment with three buoyancy tanks, a left tank 3, a middle tank 4, and a right tank, 5. This is an exemplary embodiment and should not be construed as limiting. In another embodiment, the buoyancy control system may have only one buoyancy tank in any location in the buoyancy control system. In another embodiment, the buoyancy control system may have two or more buoyancy tanks, in any number of location combinations. The buoyancy tank can be either rigid or flexible. In some embodiments, the buoyancy tank may be a standard gas cylinder. In other embodiments, the buoyancy tank may be a pressure vessel. In further embodiments, the buoyancy tank may be a high pressure cylinder. In some embodiments, the buoyancy tank may be a pressure cylinder certified to international or national standards.
[0010] In the present embodiment, the buoyancy control system comprises a storage tank, 6. In one embodiment, a storage tank is a means for compressing a gas in the buoyancy control system. In a further embodiment, a storage tank is a means for reducing the volume of a gas in the buoyancy control system, which results in decreased buoyancy. In another embodiment, it is a means for changing the location of a gas. In yet another embodiment, it is a means for changing the volume of a gas in a discrete location of the buoyancy control system. FIG. 1 shows an embodiment with a left storage tank, 6, and a right storage tank, 7. This is an exemplary embodiment and should not be construed as limiting. In another embodiment, the buoyancy control system may have only one storage tank in any location in the buoyancy control system. In another embodiment, the buoyancy control system may have two or more storage tanks, in any number of location combinations. The storage tank can be either rigid or flexible. In some embodiments, the storage tank may be a standard gas cylinder. In other embodiments, the storage tank may be a pressure vessel. In further embodiments, the storage tank may be a high pressure cylinder. In some embodiments, the storage tank may be a pressure cylinder certified to international or national standards. In some embodiments, the storage tank is a pressurized storage tank.
[0011] In the present embodiment, the buoyancy control system comprises a control unit, 8. The control unit is a means for controlling the buoyancy control system. Moreover, it is a means for determining a pressure, a pressure differential, or an orientation of the buoyancy control system. It is also a means for adjusting a flow of a gas by controlling a pump or a valve. In the present embodiment, the control unit is part of a control arrangement, further comprising at least one pressure sensor, 9. A pressure sensor is a means for detecting a pressure of a gas or a liquid. This is an exemplary embodiment and should not be construed as limiting. In another embodiment, the control arrangement has no pressure sensors. In another embodiment, the control arrangement comprises a single pressure sensor. In further embodiments, the control arrangement comprises a plurality of pressure sensors located in or around the buoyancy tanks, the walls of the buoyancy control system, and the storage tanks. One skilled in the art would understand that the pressure sensors may be any device which measures pressure, force, or density, including but not limited to load cells, transducers, strain gauges, manometers, and piezoelectric sensors.
[0012] In one embodiment, the control arrangement comprises a pressure sensor coupled with the control unit, which contains circuitry for determining a pressure at least partially based on a reading of the pressure sensor. In a further embodiment, the control arrangement comprises a first pressure sensor and a second pressure sensor, both of which are coupled to the control unit, which contains circuitry or other means for comparing a pressure reading from the first pressure sensor against a pressure reading from the second pressure sensor. In another embodiment, the control arrangement comprises a plurality of pressure sensors coupled to the control unit. The control unit contains circuitry for determining the pressures at each pressure sensor based at least partially on a reading from each sensor, and comparing the pressures at each pressure sensor to one another. In a further embodiment, the control unit contains circuitry for comparing a reading of a pressure sensor to at least one preset pressure threshold.
[0013] In the present embodiment, the control arrangement comprises at least one gyroscope, 10. A gyroscope is a means for detecting an orientation of the buoyancy control system, the orientation consisting of the roll, pitch, and yaw of the buoyancy control system. This is an exemplary embodiment and should not be construed as limiting. In the present embodiment, the gyroscope is coupled with the control unit, which contains circuitry for determining an orientation at least partially based on a reading of the at least one gyroscope. In another embodiment, the control arrangement comprises a plurality of gyroscopes. The control unit contains circuitry for comparing the readings of each gyroscope and determining an orientation at least partially based on a reading of the at least one gyroscope. One skilled in the art would understand that the gyroscope can be any of a number of known gyroscope technologies, including but not limited to a Micro Electro-Mechanical System, a fiber optic gyroscope, a hemispherical resonator gyroscope, a vibrating structure gyroscope, a dynamically tuned gyroscope, a London moment gyroscope, and an accelerometer or plurality of accelerometers.
[0014] FIG. 2 depicts an exemplary control arrangement. In the present embodiment, the control arrangement comprises at least one pressure sensor, circuitry for determining a pressure at least partially based on a reading of the at least one pressure sensor, at least one gyroscope, circuitry for determining an orientation at least partially based on a reading of the at least one gyroscope, and circuitry for adjusting a flow of a gas at least partially based on a pressure and the orientation of the buoyancy control system. In another embodiment, the control arrangement comprises at least a first pressure sensor, at least a second pressure sensor, circuitry for determining a comparative pressure between the first pressure sensor and the second pressure sensor, at least one gyroscope, circuitry for determining an orientation at least partially based on a reading of the at least one gyroscope, and circuitry for adjusting a flow of a gas at least partially based on the comparative pressure and the orientation of the buoyancy control system. In a further embodiment, the control arrangement comprises circuitry for adjusting a flow of a gas at least partially based on the comparative pressure and the orientation of the buoyancy control system, wherein the adjusting the flow of the gas alters the volume of gas in the at least one buoyancy tank.
[0015] Returning now to FIG. 1, the present embodiment of the buoyancy control system further comprises a gas pump, 11. A pump is a means for moving the gas through the buoyancy control system. In the present embodiment, the pump is triggered by the control unit in the control arrangement, based at least partially on the pressure or orientation determination from the control unit circuitry. In another embodiment, a pump may be replaced with a valve or a plurality of valves. In a further embodiment, valves may be one way valves. In that particular embodiment, one way valves would support a single flow direction, allowing gas to move in only one direction through the entire closed loop system. In one embodiment, this may enable a passive system, in which gas moved from a higher pressure tank into a lower pressure tank. Conversely, a one way valve may enable a passive system that prevents gas from moving from a higher pressure tank to a lower pressure tank. In another embodiment, valves may be two way valves. In another embodiment, a pump may be used in conjunction with a valve in order to control and move the gas in the buoyancy control system. In another embodiment, a pump may be used without a valve, relying only on the structure and function of the pump to move and prevent movement of gas in the system. In one embodiment, there may be a plurality of pumps. In one embodiment, there may be a plurality of valves.
[0016] FIG. 1 also depicts a casing, 12, around the buoyancy control system. In the present embodiment, the casing is designed to withstand pressures on the ocean floor, up to 16,000 pounds per square inch. This is an exemplary embodiment and should not be construed as limiting. In another embodiment, the buoyancy control system is designed without a high pressure casing. In this embodiment, the control arrangement includes a first pressure sensor to measure an external pressure, such as the water pressure on the external surfaces of the buoyancy control system, a second pressure sensor to measure an internal pressure, such as the pressure inside a buoyancy tank, circuitry for determining a comparative pressure between the first pressure sensor and the second pressure sensor, and circuitry for adjusting the internal pressure based on the comparative pressure determination. In this embodiment, the control unit autonomously adjusts the pressure in the buoyancy tanks to be at or near the pressure exerted by the column of water. This allows the buoyancy tanks to be uncovered, which allows for more accurate and fine adjustments in the buoyancy of the remotely operated vehicle. Furthermore, it allows for a controlled rate of descent or ascent of the remotely operated vehicle.
[0017] Not depicted are the various transporting means in the present embodiment. Transporting means are tubes or hoses are connecting the elements of the buoyancy control system and moving gases between those elements. In the present embodiment, transporting means may be used to couple a storage tank with a buoyancy tank. In another embodiment, transporting means may be used to couple a first storage tank with a second storage tank. In another embodiment, transporting means may be used to couple a first buoyancy tank with a second buoyancy tank. Transporting means may be rigid or flexible. Transporting means may be off-the-shelf transporting means. Alternatively, transporting means may be high pressure transporting means. Transporting means may be certified to national or international standards. One skilled in the art would understand that the exact configuration of tubes and hoses will necessarily depend on the particular embodiment employed.
[0018] Also not depicted are the various conducting means in the present embodiment. In the present embodiment, conducting means may be used to carry signals between a control arrangement and the tanks. In another embodiment, conducting means may be used to carry signals between a control arrangement and pumps. In another embodiment, conducting means may be used to carry signals between a control arrangement and valves. In another embodiment, conducting means may be used to carry signals between a pressure sensor and a control unit. In another embodiment, conducting means may be used to carry signals between a gyroscope and a control unit. One skilled in the art would understand that conducting means includes but is not limited to metallic and non-metallic wires, fiber optics, and wireless transmission signals.
[0019] In an exemplary embodiment, the buoyancy control system is comprised of a buoyancy tank, a storage tank coupled to the buoyancy tank, and a control arrangement coupled to the storage tank. In a further embodiment, the control arrangement contains a pressure sensor. When the control unit determines that the ambient pressure is above a threshold, the control unit allows some gas to move from the storage tank to the buoyancy tank, providing more buoyancy and lifting the remotely operated vehicle. When the control unit detects that the ambient pressure is below a threshold, the control unit allows some gas to move from the buoyancy tank to the storage tank, providing less buoyancy and dropping the remotely operated vehicle. One skilled in the art would understand that the gas in the storage tank is under extreme pressure, reducing the volume and allowing the decrease in buoyancy. This is an aspect that makes the present invention unique, because it is, in part, what enables a closed-loop system.
[0020] In another exemplary embodiment, the buoyancy control system is comprised of a buoyancy tank, a storage tank coupled to the buoyancy tank, and a control arrangement coupled to the storage tank. In a further embodiment, the control arrangement contains a plurality of pressure sensors. For example, the buoyancy control system may have a pressure sensor to measure ambient pressure and a pressure sensor to measure the pressure in a buoyancy tank. In this embodiment, the control unit contains circuitry for comparing a pressure reading from the first pressure sensor against a pressure reading from the second pressure sensor. The control unit then allows gas to move in or out of the buoyancy tank to maintain a particular pressure differential. This embodiment is what allows the buoyancy control system to function absent the high pressure casing, because it can autonomously adjust the pressure in the buoyancy tanks to withstand the pressure exerted by the column of water above the remotely operated vehicle to which the buoyancy control system is coupled.
[0021] In another exemplary embodiment, the buoyancy control system is comprised of a plurality of buoyancy tanks, a storage tank coupled with the plurality of buoyancy tanks, and a control arrangement coupled with the pressurized storage tank. In a further embodiment, the control arrangement contains a gyroscope. In this embodiment, the control unit determines an orientation of the buoyancy control system, and therefore the remotely operated vehicle, based at least partially on the reading of the gyroscope. Based at least partially on that orientation determination, the control unit then allows gas to move in or out of the plurality of buoyancy tanks to alter the orientation. One skilled in the art would understand that this embodiment allows the buoyancy control system to control the roll, pitch, and yaw, as well as the depth, of the remotely operated vehicle.
[0022] Those skilled in the art will appreciate that the foregoing specific exemplary processes and/or devices and/or technologies are representative of more general processes and/or devices and/or technologies taught elsewhere herein, such as in the claims filed herewith and/or elsewhere in the present application.
[0023] The claims, description, and drawings of this application may describe one or more of the instant technologies in operational/functional language, for example as a set of operations to be performed by a computer. Such operational/functional description in most instances would be understood by one skilled the art as specifically-configured hardware (e.g., because a general purpose computer in effect becomes a special purpose computer once it is programmed to perform particular functions pursuant to instructions from program software).
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