SUBMERSIBLE VEHICLE WITH A FLOODABLE ACTUATOR VESSEL

TECHNICAL FIELD

Example embodiments generally relate to submersible vehicle systems and, in particular, relate to structural design for high-pressure, underwater environments.

BACKGROUND

Submersible undersea vehicles, particularly unmanned vehicles, can reach depths where extreme pressures are applied to the external body of the vehicle. Such depths can place enormous pressures on internal components of the submersible vehicles, potentially leading to pressure-related failures of internal cavities and components, such as electronic components disposed within the internal cavities. In some instances, a hull breach can lead to a catastrophic implosion and loss of the vehicle. Due to this risk, in conventional submersible vehicles, substantial efforts are taken to, for example, increase the reliability and durability of seals and increase the structural strength of the hull in an effort to avoid a failure. However, such approaches are always prone to have some failure rate, certainly at deeper depths and higher pressures.

BRIEF SUMMARY OF SOME EXAMPLES

According to some example embodiments, a submersible vehicle is provided. The submersible vehicle may comprise a propulsion assembly, a pressure vessel, and a floodable actuator vessel. The propulsion assembly may comprise a motor and a propeller. The pressure vessel may comprise a pressure shell and a bulkhead. The bulkhead may be configured to seal the pressure shell to prevent fluid intrusion into an interior cargo compartment of the pressure shell when the submersible vehicle is submersed into a fluid. The floodable actuator vessel may be coupled to the pressure vessel. The floodable actuator vessel may comprise a floodable shell and a plurality of actuators. The floodable shell may comprise a plurality of flood openings configured to permit fluid intrusion into an interior flood space of the floodable shell when the submersible vehicle is submersed into a fluid. Each actuator, of the plurality of actuators, may be disposed within the interior flood space and affixed to an interior surface of the floodable shell at an actuator opening through which an external fin is actuated to maneuver the submersible vehicle in coordination with the propulsion assembly.

According to some example embodiments, a floodable actuator vessel of a submersible vehicle is provided. The floodable actuator vessel may comprise a floodable shell, a plurality of external fins, and a plurality of actuators. The floodable shell may comprise a plurality of flood openings configured to permit fluid intrusion into an interior flood space of the floodable shell when the submersible vehicle is submersed into a fluid. Each actuator, of the plurality of actuators, may be disposed within the interior flood space and affixed to an interior surface of the floodable shell at an actuator opening through which a respective external fin of the plurality of external fins is actuated to maneuver the submersible vehicle.

According to some example embodiments, a method of operating a submersible vehicle is provided. The submersible vehicle may comprise a pressure vessel coupled to a floodable actuator vessel. The method may comprise flooding an interior flood space of a floodable shell of the floodable actuator vessel with a fluid due to submersion of the submersible vehicle into the fluid. The fluid may flood into the interior flood space via a plurality of flood openings in the floodable shell. A plurality of actuators may be disposed within the interior flood space. The plurality of actuators may be affixed to a plurality of external fins that extend from an exterior surface of the floodable shell. The method may also comprise preventing intrusion of the fluid into an interior cargo compartment of a pressure shell of the pressure vessel despite submersion of the submersible vehicle into the fluid. The interior cargo compartment may be air-filled. A controller may be disposed within the interior cargo compartment. The method may also comprise controlling, via the controller, an output of electrical signals to the plurality of actuators and a motor of a propulsion assembly to maneuver the submersible vehicle while the interior flood space of the floodable shell is flooded and the interior cargo compartment is air-filled.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described some example embodiments in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

FIG. 1 illustrates a cross-section, block diagram of an example submersible vehicle according to some example embodiments;

FIG. 2 illustrates a perspective view of an example submersible vehicle according to some example embodiments;

FIG. 3 illustrates a perspective view of an example submersible vehicle with forward vessel components removed according to some example embodiments;

FIG. 4 illustrates a perspective exploded view of a pressure vessel according to some example embodiments;

FIG. 5 illustrates a perspective zoomed view of a bulkhead according to some example embodiments;

FIG. 6 illustrates a portion of a submersible vehicle that includes the floodable actuator vessel, a rear cone, and a propulsion assembly according to some example embodiments;

FIG. 7 illustrates an exploded view of the portion of the submersible vehicle shown in FIG. 6 according to some example embodiments;

FIG. 8 illustrates an isolated view of a floodable shell according to some example embodiments;

FIG. 9 illustrates an isolated view of an actuator affixed to an external fin according to some example embodiments;

FIG. 10 illustrates a side view of the portion of the submersible vehicle shown in FIG. 6 according to some example embodiments;

FIG. 11 illustrates a front view of the portion of the submersible vehicle shown in FIG. 6 according to some example embodiments;

FIGS. 12A-12C illustrate front views of the portion of the submersible vehicle shown in FIG. 6 with foam disposed within the interior flood space according to some example embodiments; and

FIG. 13 illustrates a block diagram of a method of operating a submersible vehicle according to some example embodiments.

DETAILED DESCRIPTION

Some example embodiments will now be described more fully with reference to the accompanying drawings, in which some, but not all example embodiments are shown. Indeed, the examples described and pictured herein should not be construed as being limiting as to the scope, applicability, or configuration of the present disclosure. Rather, these example embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. The term “or” as used herein is defined as the logical or that is true if either or both are true.

According to some example embodiments, a submersible vehicle is provided that may comprise a plurality of structural portions, with at least one of the structural portions being configured to flood when the vehicle is submerged in a fluid (e.g., water). The floodable structural portion may, according to some example embodiments, provide support for active components of the vehicle, such as fin actuators. As such, according to some example embodiments, such a floodable structural portion may be a floodable actuator vessel. A floodable actuator vessel, according to some example embodiments, may comprise a floodable shell and a plurality of actuators. The floodable shell may be a structural component to which the actuators are affixed. The floodable shell may define an interior volume that may be referred to as an interior flood space that floods or fills with fluid when the floodable actuator vessel is submerged. The floodable shell may include a plurality of flood openings through which fluid passes to flood the interior flood space.

According to some example embodiments, the submersible vehicle may be modular and the floodable actuator vessel may be one of a plurality of the separate modular vessels of the submersible vehicle. Together, the vessels may be components of a body or fuselage of the submersible vehicle. In addition to the floodable actuator vessel, the body or fuselage of the submersible vehicle may include one or more pressure vessels. A pressure vessel may be sealed such that, unlike the floodable actuator vessel, the pressure vessel does not permit fluid to enter into an internal volume of the pressure vessel, which may be referred to as the interior cargo space or compartment of the pressure vessel. This internal cargo space may be used to house more sensitive operating components that cannot be exposed to the flooded conditions of the floodable actuator vessel. Such components may include, for example, electronic components. According to some example embodiments, the interior cargo compartment may be filled with a non-conductive fluid such as air, oil, or the like. The interior cargo compartment may be defined and surrounded by a pressure shell of the pressure vessel that is sealed by one or more bulkheads (e.g., removable bulkheads) that attach to the pressure shell.

The inclusion of a floodable actuator vessel in the context of, for example, a submersible vehicle, solves various technical problems associated with conventional system that employ pressure vessels to house active components. In this regard, many conventional systems use pressure vessels to house components that cause the movement of mechanical members such as shafts or transmissions. Such components may be actuators, such as servos, solenoid actuators, motors, or the like. These components may drive, for example, a rotatable shaft that may need to pass through an opening in the sidewall or bulkhead of a pressure vessel to engage with a mechanical load. In some instances, the mechanical load, such as a fin, may be disposed external to the body or fuselage of the submersible vehicle, and, as such, seals may be required that allow for mechanical movement, while also preventing intrusion of the external fluid into the pressure vessel. Since these seals may be subjected to high pressures, the seals are frequent failure points that can lead to complete failures of the submersible vehicle.

The floodable actuator vessel, according to some example embodiments, solves this technical problem by eliminating the pressure difference between the interior flood space of the floodable actuator vessel and the external environment of the floodable actuator vessel. In this regard, due to the flood openings that permit external fluid to enter the floodable actuator vessel, the need for shaft seals and like is eliminated and the pressure between the interior flood space and the external environment is equalized. As such, no comparable seals for the floodable shell may be required.

Additionally, conventional pressure vessels may require high-strength materials and structural designs to operate at depths that create high implosion forces on the pressure vessels. Such high strength materials and structural designs may increase cost and complexity of implementation. Such technical problems can be overcome by implementation of a floodable actuator vessel, according to some example embodiments. Since the internal and external pressures for the floodable actuator vessel are equal (i.e., no pressure delta or difference), a high-strength floodable shell is not required. In other words, according to some example embodiments, the floodable shell of the floodable actuator vessel may be constructed of relatively low-strength, lower cost materials that could not be used in the context of a pressure vessel. Moreover, since the pressure difference is not an issue in the floodable actuator vessel, the design of the floodable shell may be simplified and less complex. As a result, for example, the implementation of the floodable actuator vessel makes different materials and designs available to use for the floodable shell. Additionally, different manufacturing techniques may also become available for use in manufacturing, such as, for example, three-dimensional printing techniques. As such, the implementation of the floodable actuator vessel, particularly as a housing for fin actuators, provides a significant improvement over conventional systems.

Having described some aspects and benefits of some example embodiments in a general sense, some more specific example embodiments of a submersible vehicle and floodable actuator vessels will now be described. With reference to FIG. 1, a cross-section, block diagram of a submersible vehicle 100 is shown. The submersible vehicle 100 may, according to some example embodiments, be an unmanned underwater vehicle such as an underwater drone. The submersible vehicle 100 may move via remote control by a remote driver or the submersible vehicle 100 may be an autonomous vehicle that maneuvers without the need for a driver to control the movement of the submersible vehicle 100.

According to some example embodiments, the submersible vehicle 100 may comprise a nose vessel 110, an extension vessel 120, a pressure vessel 140, a floodable actuator vessel 150, a rear cone 160, and a propulsion assembly 170. According to some example embodiments, the fuselage or body of the submersible vehicle 100 may be substantially cylindrical in shape, and may therefore define a center longitudinal axis 101 that extends between a bow of the submersible vehicle 100 to the stern of the submersible vehicle 100. The following describes aspects of the submersible vehicle 100 for submersion into a fluid that is water (e.g., sea water). However, one of ordinary skill in the art would appreciate that water is but one example of a fluid that the submersible vehicle 100 may be submersed in for operation.

Moving from bow to stern, the nose vessel 110 may be a forward-most structure of the submersible vehicle 100, and may therefore have a rounded or curved front surface to provide reduced drag and turbulence as the submersible vehicle 100 moves through the water. According to some example embodiments, the nose vessel 110 may comprise a nose shell 111 that defines an internal nose space 112. According to some example embodiments, the nose shell 111 may be constructed to support efficient movement of the submersible vehicle 100 through the water. As mentioned above, the nose shell 111 may include a rounded forward external surface that may have a hemispherical shape that elongates into a cylindrical portion. According to some example embodiments, the nose shell 111 may define an internal nose space that may be sealed, for example, with a bulkhead. According to some example embodiments, the nose shell 111 may be, for example, open at its rear to permit the nose space 112 to be flooded.

According to some example embodiments, the nose vessel 110 may be configured to support components, including, for example, sensors. In this regard, according to some example embodiments, when the nose vessel 110 houses a sensor, e.g., sensor 113, the nose vessel 110 may be referred to as a sensor vessel and the nose shell 111 may be referred to as a sensor shell. The sensor 113 may be any type of sensor, such as, an optical sensor (camera), depth sensor, an echo sounder and receiver, a side scan sonar, a position sensor, biologic sensor, or the like. According to some example embodiments, wiring 133 may be electrically connected to the sensor 113, which may be connected to a controller 145 that is configured to receive sensor signals via the wiring 133 from the sensor 113 that are representative of sensor measurements or captures performed by the sensor 113. As shown in FIG. 1, while a portion of the sensor 113 may be housed within the nose space of the nose shell 111, the sensor 113 may also include a probe, lens, or the like that extends through an opening in the nose shell 111 and extend external to the nose shell 111. In example embodiments where the nose shell 111 is floodable, the opening that supports the externally extended portion of the sensor need not be coupled to a seal, since the nose space is not under pressure when the submersible vehicle 100 is submersed. However, according to some example embodiments, a housing of the sensor 113 itself may be sealed and pressure or depth-rated to allow for direct interaction with water flooded into the nose space 112 without affecting the operation of the sensor 113, and to withstand high pressures that are present at large depths.

According to some example embodiments, the nose vessel 110 may be physically coupled to another vessel, for example, as shown in FIG. 1, the extension vessel 120. The extension vessel 120 may be configured to increase a longitudinal length of the submersible vehicle 100, for example, along the axis 101. In this regard, for example, the extension vessel 120 may increase the length of the submersible vehicle 100 to improve the maneuverability of the submersible vehicle 100 in water. The elongation of, for example, the cylindrical body or fuselage of the submersible vehicle 100 can operate teach or stabilize the submersible vehicle 100's movement in directions parallel to the axis 101. As such, the addition of the extension vessel 120 may be included, having a selected length, to contribute to such movement stabilization.

According to some example embodiments, since the extension vessel 120 may be primarily included to extend the length of the submersible vehicle 100, an internal extension vessel space 122 may be a floodable space. In this regard, the extension vessel 120 may include an extension shell 121, and, according to some example embodiments, the extension shell 121 may comprise a plurality of posts that extend between vessels that are adjacent to the extension vessel 120. As such, the extension shell 121 may include openings or voids between the posts that permit water to flood the interior of the extension shell 121. According to some example embodiments, based on the positioning of the extension vessel 120, the extension vessel 120 may be configured to support extension of wiring 133 through the extension vessel 120 between adjacent vessels. In this regard, for example, the extension vessel 120 may support extension of the wiring 133 through the extension vessel 120 between the pressure vessel 140 and the nose vessel 110 to support connection of the wiring 133 to the sensor 113.

Additionally, according to some example embodiments, the extension vessel 120 may be used as an exchangeable vessel to increase the design flexibility of the submersible vehicle 100. In this regard, for example, it may be beneficial to movement control to have a constant length for the submersible vehicle 100, but also allow for some degree of configurability of the submersible vehicle 100. As such, according to some example embodiments, the extension vessel 120 may be exchanged with another type of vessel, based on an application for the submersible vehicle 100. For example, rather than including the extension vessel 120, the submersible vehicle 100 may include a pressure vessel or a floodable actuator vessel, with changing the length of the submersible vehicle 100. If additional seal cargo space is needed, then a pressure vessel may be used in place of the extension vessel 120. Alternatively, if it is determined that, for example, the submersible vehicle 100 would benefit from forward positioned actuating fins, the extension vessel 120 may be replaced with a floodable actuator vessel to support such configuration.

As mentioned above, the submersible vehicle 100 may also include a pressure vessel 140. The pressure vessel 140 may comprise a pressure shell 141. According to some example embodiments, the pressure shell 141 may be a tubular or cylindrical element having an internal space for cargo, which may be referred to as the interior cargo compartment 142. The pressure shell 141 may be formed from a material that, when formed into a cylindrical shape, can withstand high externally applied pressures (e.g., to depth in water) without collapsing.

As mentioned above, the pressure vessel 140 may be sealed and therefore have a pressure difference between its internal pressure and external pressure. To permit accessibility to the interior cargo compartment 142 when the submersible vehicle 100 is not submerged, but seal the interior cargo compartment when the submersible vehicle 100 is submerged, the pressure vessel 140 may include one or more bulkheads, such as bulkheads 131 and 132 shown in FIG. 1. In the example embodiment of FIG. 1, the pressure shell 141 comprises a cylindrical tube that is open at its ends. However, the bulkheads 131 and 132 may be configured to be removed to permit access into the interior cargo compartment 142 to install or maintain internal components and installed onto a respective end of the pressure shell 141 to seal the interior cargo compartment 142. According to some example embodiments, the bulkheads 131 and 132 may include, for example, compressible ring seals that are disposed between the bulkhead and the pressure shell 141 to form an air-tight seal. According to some example embodiments, the bulkheads 131 and 132 and the ends of the pressure shell 141 may be correspondingly threaded to permit the bulkheads 131 and 132 to be installed by screwing the bulkheads 131 and 132 onto the respective ends of the pressure shell 141.

Additionally, according to some example embodiments, the bulkheads 131 and 132 may include penetrators configured to permit wiring 133 from exiting or entering the pressure vessel 140. In this regard, the pressure vessel 140's connectively to the other portions of the submersible vehicle 100 may be via the penetrators. The penetrators, as further described below, are configured to maintain a seal while also permitting wiring 133 to pass through the bulkheads 131 and 132 via their respective penetrators. According to some example embodiments, wiring 133 may be a single cable or a number of separate wires or cables. If wiring 133 is a single cable, then, for example, the bulkheads 131 and 132 may have a single penetrator for the single cable. However, if the wiring 133 is made up of a number of separate wires or cables, the bulkheads 131 and 132 may a plurality of respective penetrators.

As described herein, the bulkheads 131 and 132 with their penetrators may support the electrical connection of the components within the interior cargo compartment 142 to other components of the submersible vehicle 100. However, according to some example embodiments, the bulkheads 131 and 132 need not support mechanical movement connections between components of the submersible vehicle 100. As such, according to some example embodiments, all mechanical movement components and connections may be disposed external to the pressure vessel 140, and only electrical signals originate or terminate within the pressure vessel 140.

Since the pressure vessel 140 may be a pressurized component, the connection of the bulkheads 131 and 132 with the pressure shell 141 may form a robust, high pressure component. In this regard, as mentioned above, the materials used to form the pressure vessel 140 may be strong and reliable. In this regard, for example, the pressure shell 141 may, according to some example embodiments, be formed of a material and have a designed structure to support operation of the submersible vehicle 100 at selected depths and associated pressures. In this regard, the pressure shell 141 may have a high impact strength based on its materials and structural design. Impact strength may be the capability of a material or component to withstand a suddenly applied force load due to the distribution of forces. The pressure shell 141 may also have a high compressive strength, where compressive strength is a limit of compressive stress that causes ductile or brittleness failure of the material. The pressure shell 141 may also have a high fatigue strength, where fatigue strength is a measure of the strength of a material or component in view of several loading processes implemented on the material or component. Finally, the pressure shell 141 may also have a high plasticity, where plasticity is indicative of a measure of strain that can be applied without being recoverable.

Due to the sealed nature of the pressure vessel 140, electronic and other components that may be disposed within the interior cargo compartment 142 of the pressure vessel 140. In this regard, according to some example embodiments, a battery 143, an inertial measurement unit (IMU) (or navigation system) 144, a controller 145, and other components may be disposed within the interior cargo compartment 142. The battery 143, the IMU 144, and the controller 145 may be connected via the wiring 133, which may be configured to electrically connect the battery 143, the IMU 144, and the controller 145 with each other and with other components of the submersible vehicle 100. The battery 143 may be, for example, the power source for submersible vehicle 100 that supplies power to all electric and electromechanical components of the extension vessel 120. According to some example embodiments, the battery 143, which may be rechargeable, may be a heavier component of the submersible vehicle 100 and may be positioned, for example, in a more central position to balance the weight of the submersible vehicle 100 between the bow and the stern.

The navigation system 144 may include or be embodied by, for example, a type of position sensor that facilitates navigation of the submersible vehicle 100. According to some example embodiments, the navigation system 144 may be, for example, an inertial navigation system (INS) that may comprise an inertial measurement unit (IMU). The navigation system may include a variety of sensors and components to support positioning and navigation of the submersible vehicle 100 such as accelerometers, gyroscopes, electronic compasses, gravitometers, and the like. In addition to being used to determine a position of the submersible vehicle 100, the navigation system 144 may be configured to determine an orientation of the submersible vehicle 100 with respect to pitch, roll, and yaw. In some example embodiments, the navigation system 144 may be configured to determine a position using relative tracking techniques since, for example, global positioning system (GPS), signal may not be receivable while the submersible vehicle 100 is submersed. As such, in some example embodiments, the navigation system 144 may not directly determine position from, for example, GPS sources, but may rather assess local movement, inertia, and momentum to determine a position of the submersible vehicle 100. According to some example embodiments, GPS signals may not penetrate to a depth of operation for the submersible vehicle 100 and therefore a non-GPS position detection technology can be used to still determine a position of the submersible vehicle 100. However, when the submersible vehicle 100 is surfaced, or otherwise when GPS signals can be received, the navigation system 144 may leverage a GPS sensor to determine a position of the submersible vehicle 100 or error correct position determinations based on, for example, inertia and momentum.

The controller 145 may be circuitry configured to control the operation of the submersible vehicle 100. The controller 145 may comprise a processor and a memory. Further, according to some example embodiments, controller 145 may be configurable to perform various operations as described herein, including the operations and functionalities described with respect to maneuvering the submersible vehicle 100 either by receiving communicated movement instructions or implementing autonomous maneuvering. In some embodiments, the controller 145 may be embodied as a chip or chip set. In other words, the circuitry may comprise one or more physical packages (e.g., chips) including materials, components or wires on a structural assembly (e.g., a baseboard). The controller 145 may be configured to receive inputs (e.g., from peripheral components, such as sensors), perform actions based on the inputs, and generate outputs (e.g., maneuver the submersible vehicle 100). Moreover, the controller 145 may be embodied as a circuit chip (e.g., an integrated circuit chip, such as a field programmable gate array (FPGA), and application specific integrated circuit (ASIC)) configured (e.g., with hardware, software or a combination of hardware and software) to perform operations described herein. In an example embodiment, the memory mentioned above may include one or more non-transitory memory devices such as, for example, volatile or non-volatile memory that may be either fixed or removable. The memory may be configured to store information, data, applications, instructions or the like for enabling, for example, the functionalities described with respect to the submersible vehicle 100 to be performed.

The controller 145 may be configured to control various aspects of the operation of the submersible vehicle 100. In this regard, the controller 145 may be configured to control operation of one or more sensors, e.g., sensor 113, and retrieve sensor measurements. Further, the controller 145 may control the operation of the submersible vehicle 100 based on the sensor measurements. Further, according to some example embodiments, the controller 145 may be configured to control movement of the submersible vehicle 100 via controlled operation of fin actuators and a motor 171 of the propulsion assembly 170. Additionally, the controller 145 may be configured to output electrical signals to control actuation of the actuators of the floodable actuator vessel 150 and also control the rotational speed of the motor 171. The controller 145 may interface with other components of the submersible vehicle 100 through the wiring 133, which may be embodied as electrical wires that pass through, for example, the penetrators of the bulkheads 131 and 132.

The floodable actuator vessel 150 may be operably coupled to the pressure vessel 140, for example, via physical connection to the bulkhead 132. According to example embodiments where the submersible vehicle 100 is modular, the floodable actuator vessel 150 may be removably coupled to the bulkhead 132 such that the floodable actuator vessel 150 may be removed from connection to the bulkhead 132 and installed onto the bulkhead 132. As described above, the floodable actuator vessel 150 may comprise a floodable shell 158 and a plurality of actuators (e.g., actuators 153 and 155). Additionally, according to some example embodiments, the floodable actuator vessel 150 may also comprise a plurality of external fins (e.g., external fins 154 and 156). Such external fins may be moveable under the control of the actuators to change the positioning of the control surfaces of the fins to maneuver the submersible vehicle 100. The floodable actuator vessel 150 may be positioned toward the rear or stern of the submersible vehicle 100 with the propulsion assembly 170 to facilitate maneuverability of the submersible vehicle 100. According to some example embodiments, the floodable actuator vessel 150 may be positioned between the pressure vessel 140 and the propulsion assembly 170, which may be disposed at the stern and positioned as the rearmost component of the submersible vehicle 100. As such, according to some example embodiments, the floodable actuator vessel 150, as shown in FIG. 1, may be referred to as a tail section or components of the submersible vehicle 100.

The floodable shell 158 may be, for example, a primary structural component of the floodable actuator vessel 150. According to some example embodiments, the floodable shell 158 may be substantially cylindrical in shape, and may thereby define an interior space referred to as the interior flood space 151. The plurality of actuators, including actuators 153 and 155, may be disposed within the interior flood space 151 and affixed to an internal surface of the floodable shell 158. Although the interior flood space 151 may have components disposed within this space, the interior flood space 151 may also be configured to be flooded, for example, by water when the submersible vehicle 100 is submerged. To do so, the floodable shell 158 may include a plurality of flood openings 152. In this regard, the plurality of flood openings 152 may be configured to permit fluid intrusion into an interior flood space 151 when the submersible vehicle 100 is submersed and allow the interior flood space 151 to empty when the submersible vehicle 100 is no longer submersed (e.g., removed from the water).

The actuators of the floodable actuator vessel 150 (e.g., actuators 153 and 155) may, according to some example embodiments, be self-enclosed devices that are pressure and/or depth rated and affixed to the floodable shell 158. The actuators may be disposed within the interior flood space 151 and affixed to an interior surface of the floodable shell 158 at an actuator opening. According to some example embodiments, each actuator may be coupled, via an actuator shaft, to a respective external fin (e.g., external fin 154 and 156), and the external fins may be actuated (e.g., rotated) to maneuver the submersible vehicle 100 in coordination with the propulsion assembly 170. Each actuator shaft may extend from the interior flood space 151 through an actuator opening and into a space external to the floodable shell 158. The actuators 153 and 155 may be controlled by the controller 145 via the wiring 133. Additionally, electrical wires of the wiring 133 may also pass through the interior flood space 151 of the floodable shell 158 to provide an interface to the controller 145 to control operation of the motor 171 of the propulsion assembly 170.

Because the floodable shell 158, according to some example embodiments, is not subjected to an interior/exterior pressure difference, the materials used to construct the floodable shell 158 need not have high strength characteristics. Relative the materials and structural design of the pressure shell 141, the floodable shell 158 may use relatively lesser strength materials. In this regard, relative to the material of the pressure shell 141, the material used to form the floodable shell 158 may have a higher plasticity, a lower impact strength, a lower compressive strength, and a lower fatigue strength. As such, the relatively brittle characteristics of three-dimensional (3D) printed plastic materials can be used to form the floodable shell 158.

Rearward of the floodable actuator vessel 150, the submersible vehicle 100 may include a transitional vessel formed as a rear cone 160. The rear cone 160 may be configured to reduce a diameter to of the body or fuselage of the submersible vehicle 100 to provide an inflow path for water into the propulsion assembly 170 for propulsion. As such, the propulsion assembly 170 may be affixed to the smaller diameter end of the rear cone 160.

The propulsion assembly 170 may comprise the motor 171 and a propeller 172. Additionally, according to some example embodiments, propulsion assembly 170 may also include a propeller shield 173, although some example embodiments do not include a propeller shield 173. The motor 171 may be an electric motor and a rotation speed and direction may be controllable by the controller 145 via the wiring 133. The motor 171 may cause the propeller 172 to rotate thereby creating a thrust to propel the submersible vehicle 100. To protect the propeller 172 from interacting with hazardous surfaces (e.g., rocks, other vehicles, and the like) the propeller shield 173 may be formed as a cylindrical ring that encircles the propeller 172. The propeller shield 173, or ducting, may, according to some example embodiments, have an open-ended cylinder shape, which may not only protect the propeller, but may also contribute to efficient water flow through the propeller to increase maneuverability with reduced power utilization.

As mentioned above, the use of a floodable vessel can be beneficial because the pressures applied to the vessel internally and externally are equalized. This contrasts with the pressures affecting the pressure vessel 140, which, due to having a sealed compartment, internal and external pressure may be different. In this regard, when submerged, a pressure within the interior cargo compartment 142 of the pressure vessel 140 may be different from an external pressure applied to body or fuselage of the submersible vehicle 100 due to the depth of submersion. Since the pressure within the interior flood space 151 may be same as the external pressure, the pressure within the interior cargo compartment 142 may be different from the pressure in the interior flood space 151. Additionally, since the pressure within the interior flood space 151 may be same as the external pressure, the pressures applied to an actuator shaft that extends from the interior flood space 151 into the external environment of the submersible vehicle 100 are the same, i.e., uniform across the external surface of the actuator shaft, and, as a result, no seal or the like is needed for application to actuator shaft.

According to some example embodiments, the floodable actuator vessel 150 may also comprise foam 157 that may operate to assist with buoyancy and level or on-plane operation submersible vehicle 100. In this regard, due to the weight of the actuators and the external fins, the floodable actuator vessel 150 may be a heavier vessel of the submersible vehicle 100. Further, due to its location near the stern and the weight of the propulsion assembly 170, the submersible vehicle 100 may be heavier at the rear of the body or fuselage, which, if left uncompensated, would tend to cause the center of gravity to be shifted rearward thereby causing the bow or forward end of the submersible vehicle 100 to be pointed upwards. The addition of foam 157 to the floodable actuator vessel 150 may counteract this rearward shifted center of gravity when the submersible vehicle 100 is submersed to cause the submersible vehicle 100 to operate on a level plane.

In this regard, the foam 157 may be, for example, a shaped block of foam that fits within the interior flood space 151 with the actuators. According to some example embodiments, the foam may be alternatively be a foam paste that is injected into the interior flood space 151 and cures in place. According to some example embodiments, because the foam 157 may be exposed to high pressures, the foam 157 may be a syntactic foam. According to some example embodiments, a syntactic foam may be comprised of composite materials synthesized by filling a metal, polymer, cementitious or ceramic matrix with hollow spheres called microballoons or cenospheres or non-hollow spheres as aggregates that are resilient in the presence of high pressures.

Additionally, according to some example embodiments, because the interior of the floodable actuator vessel 150 may be flooded, the foam 157 may be disposed within the interior, i.e., with in the interior flood space 151 of the floodable actuator vessel 150. Further, according to some example embodiments, the foam 157 may embodied as one or more foam components that may be positioned, for example, such that the center longitudinal axis 101 passes through a central the foam component. Additionally or alternatively, in some example embodiments, foam components may be distributed into locations within the flood space 151, for example in voids between, for example, the actuators 153 and 155 and other actuators. As further described below, the foam components may be formed in standard shapes (e.g., rectangular cubes, cylinders, etc.) or the foam components may be formed to fit into their respective voids.

Regardless of the locations and shapes, according to some example embodiments, the foam components may be positioned to generate a center of buoyancy that is aligned with a center longitudinal axis 101 of submersible vehicle 100, which may simplify the efforts undertaken to determine the quantity of foam needed and placement of that foam for level plane operation of the submersible vehicle 100. Such positioning of the foam components may be advantageous relative to foam-based or other buoyancy compensation approaches that are disposed external to the body or fuselage of the submersible vehicle 100, which may create drag and turbulence when the submersible vehicle 100 is maneuvering. Accordingly, the addition of the foam components internal to the body or fuselage provides buoyancy to the floodable actuator vessel 150 to compensate for, for example, the weight of the actuators, the plurality of external fins, and the adjacent, rear-mounted motor.

Now referring to FIGS. 2-12, an example embodiment of the submersible vehicle 100 is shown in more detail relative to the block diagram of FIG. 1. In this regard, FIG. 2 illustrates a perspective view of an example submersible vehicle 100 according to some example embodiments. As shown in FIG. 2, the submersible vehicle 100 includes a nose vessel 110 comprising a nose shell 111 that defines a nose space 112. The nose shell 111 may support the sensor 113. The nose shell 111 of FIG. 2 is open at its rear and therefore the interior nose space 112 is floodable. The nose shell 111 may be affixed to the extension vessel 120, which comprises an extension shell 121 that defines an internal extension vessel space 122 that is also floodable due to the opening between the posts of the extension shell 121.

The pressure vessel 140 may be affixed to the extension shell 121 via the bulkhead 131, which may include features for permitting wiring to pass through the bulkhead 131 while maintaining a seal for the interior cargo compartment. The pressure vessel 140 may also include a bulkhead 132 that connects to the floodable actuator vessel 150 and the floodable shell 158 of the floodable actuator vessel 150.

In FIG. 2, the floodable shell 158 may contain the actuators and the interior flood space. The floodable shell 158 includes the flood openings 152 that are configured to permit the interior flood space to be flooded upon submersion of the submersible vehicle 100. The external fins 154 and 156 are shown extending radially away from the center longitudinal axis 101. The rear cone 160 is connected to the floodable actuator vessel 150 and also the propulsion assembly 170 including the propeller shield 173.

Referring now to FIG. 3, the submersible vehicle 100 is shown with the nose vessel 110 and extension vessel 120 omitted. Accordingly, the bulkhead 131 is shown in more detail, according to some example embodiments, with the penetrators 180 and 181. Accordingly, electrical wires of wiring 133 may pass through the bulkhead 131 via the penetrators 180.

Additionally, the cylindrical shape of the exterior of the pressure shell 141 is shown in connection with the rear bulkhead 132. The floodable actuator vessel 150 is also shown in connection with the rear bulkhead 132. The flood openings 152 are shown as circular openings that extend through the external wall of the floodable shell 158 and into the interior flood space 151. According to some example embodiments, the flood openings are positions forward of the external fins 154, 156, 184, and 186, which may be actuated via internally disposed actuators. Again, the rear cone 160 may be affixed between the floodable actuator vessel 150 and the propulsion assembly 170 including the propeller shield 173.

Now referring to FIG. 4, an exploded view of the pressure vessel 140 is shown. As can be seen the pressure vessel 140 may comprise the pressure shell 141, the bulkheads 131, and the bulkheads 132. As best seen in FIG. 4, the tubular shape of the pressure shell 141 is shown with a thickness of the pressure shell 141's wall being shown. Following from the description of the pressure shell 141 above, the pressure shell 141 may formed of a strong material such as a casted acrylic or a metal, such as aluminum. The bulkheads 131 and 132 are shown as having a narrower diameter portion 136 that may fit within the pressure shell 141. According to some example embodiments, this narrower portion 136 of the bulkheads 131 and 132 may include an external thread that can be screwed into a complementary internal thread of the pressure shell 141. Alternatively, rather than a thread, the narrower portion of the bulkheads 131 and 132 may include a series of seals (e.g., ring seals) that are press-fit into the end of the pressure shell 141 to form a fluid-tight seal. The bulkheads 131 and 132 may also include a stop plate 135 that includes side extending tabs to prevent over-insertion of the bulkheads 131 and 132 into the pressure shell 141.

FIG. 5 illustrates a zoomed view of the bulkheads 131. As can be better seen in FIG. 5, the tabs 137 extend radially from the center longitudinal axis 101, when the bulkheads 131 is assembled into the submersible vehicle 100. Again, the tabs 137 may operate as stops for preventing the bulkheads 131 by contacting the lip of the pressure shell 141. Narrower portion 136 can also be seen in greater detail.

FIG. 6 again illustrates a portion of the submersible vehicle 100 that includes the floodable actuator vessel 150, the rear cone 160 and the propulsion assembly 170. With the pressure vessel 140 and the rear bulkheads 132 omitted, a perspective view of the interior flood space 151 can be seen. Again, some of the actuators 155 and 183 can be seen being disposed within the interior flood space 151. The actuators 155 and 183 can more clearly be seen affixed to the interior surface of the floodable shell 158.

Following from FIG. 6, FIG. 7 shows an exploded view of the portion of the submersible vehicle 100 shown in FIG. 6. In this regard, all four of the actuators 153, 155, 183, and 185 can be seen with external fins 154, 156, 184, and 186 connected thereto, respectively. Additionally, the actuator openings 187 in the floodable shell 158 of the floodable actuator vessel 150, through which an actuator shaft may extend (without a seal), are also shown. These components are shown with the rear cone 160 and the propulsion assembly 170, which comprises the motor 171, the propeller 172, and the propeller shield 173.

FIG. 8 illustrates an isolated view of the floodable shell 158. As best seen in FIG. 8, the plurality of flood openings 152 are shown. According to some example embodiments, as seen in FIG. 8, the flood openings 152 may have an external profile that is planar with the surrounding external surface of the floodable shell 158. As a result, no portion of a flood opening 152 or the lip of the flood opening 152 extends in a radial external direction from the axis 101. As such, in the forward direction of motion of the submersible vehicle 100, no extension or element operates as a catch or scoop to bring water into the interior flood space 151 as a result of the motion of the submersible vehicle 100. In this manner, once the interior flood space 151 is filled, and moving through the water, the architecture of the flood openings 152 are such that no internal current within the interior flood space 151, which would cause drag, turbulence, and difficulties with maneuverability of the submersible vehicle 100. In other words, an external profile of each of the flood openings 152 may be disposed substantially parallel to a direction of fluid flow over an exterior of the submersible vehicle 100 when moving to prevent fluid flow into the interior flood space 151 and associated turbulence.

FIG. 9 illustrates a self-contained actuator 153, which may be representative of an actuator that may be used in association with the submersible vehicle 100. In this regard, the actuator 153 may comprise a housing 188, a port 189, an actuator shaft 191. The actuator shaft 191 may be affixed to an external fin 154, and the actuator shaft 191 may be controlled by the actuator 153 to rotate about the shaft axis 192, as indicated by the arrows 193. The external fin 154 may be rotatable about an axis of the actuator shaft 191 to steer the submersible vehicle 100, in cooperation with the other external fins, to move the submersible vehicle 100 to a desired location.

As mentioned above, the actuator housing 188 may be sealed and rated for high pressure, deep water environments. As such, the actuator housing 188 may be directly exposed to the water (e.g., seawater) without concern of the effect on the internal electromechanical components of the actuator. Moreover, the port 189 on the actuator housing 188 may include features that facilitate a water-tight connection with the electrical wires that control the operation of the actuator 153. In this regard, for example, the port 189 may include threading for connecting to the wiring 133 with a complementary seal nut that connects to the threading of the port 189.

Another opening in the actuator 153 is the opening for actuator shaft 191. While the housing 188 may have internal seals, due to the structure of the floodable actuator vessel 150, the actuator shaft 191 need not have any seal external the actuator housing 188 as described above. Accordingly, the actuator shaft 191 may be subject to only one pressure since the pressure on both sides of the actuator opening 187 of the floodable shell 158 is equal.

FIGS. 10-12, which show a rear portion of the submersible vehicle 100, will now be described which show a side view (FIG. 10), a front view (FIG. 11), and front views (FIGS. 12A, 12B, and 12C) with foam disposed within the interior flood space 151, as described herein. With the exception of FIG. 12A-C's inclusion of the foam components 159, the vehicle portions shown in FIGS. 10-12C follow from the perspective view of the same portion in FIG. 6.

In this regard, with respect to FIG. 10, the side view more clearly shows the alignment of the flood openings 152 with a respective external fin 186. Such aligned positioning may simplify manufacturing. However, according to some example embodiments, the positioning of the flood openings 152 in a forward portion of the floodable shell 158 and ahead of the external fin 186 tends to further limit turbulence and drag that may occur due to if the flood openings 152 were rearward of the external fin 186, where turbulence created by the fin 186 may be increased and may possibly cause undesired currents within the interior flood space 151.

FIG. 11 shows a front view of the portion of the submersible vehicle 100. As best seen in FIG. 11, the cruciform configuration of the actuators 153, 155, 183, and 185 and their respective external fins 154, 156, 184, and 186 is shown. Additionally, a thickness of the floodable shell 158 is also shown, which may be designed based on the material used to form the floodable shell 158 (e.g., 3D printing plastic material). FIGS. 12A, 12B, and 12C show the same forward view, however, with the foam components 159, configured as shaped members and positioned within the interior flood space 151 to add buoyancy to the submersible vehicle 100. The foam components 159 may be same or similar to the foam 157 described above.

Referring to FIG. 12A, the foam component 159 is centrally located within the flood space 151 such that the center longitudinal axis 101 passes through the foam component 159. In example embodiments where the flood space 151 is configured to support fluid flow through the flood space 151, the positioning of the foam component 159 in this central position does not obstruct possible fluid flow through the flow voids 161 between the actuators 153, 155, 183, and 185.

Now referring to FIG. 12B, the foam components 159 are positioned differently, which may be additional or alternative positions to the embodiment of FIG. 12A. In FIG. 12B, the four foam components 159 are included, with each being positioned within respective voids between the actuators. As shown in FIG. 12B, the foam components 159 are shaped as rectangular cubes. Accordingly, since the voids between the actuators are generally pie-shaped, the rectangular cube foam components 159 can support fluid flow through the flood space 151 since the foam components 159 do not fill the entire void. As such, the foam components 159 still allow for flow voids 161 between the actuators 153, 155, 183, and 185 to accommodate example embodiments that permit fluid flow through the flood space 151.

Now referring to FIG. 12C, the foam components 159 are positioned similar to the example embodiment of FIG. 12B, however, the foam components 159 are now form fit to the shape of the voids between the actuators. As such, the foam components 159 may have an elongated, generally pic-shaped form factor. While in some example embodiments the foam components may have no internal channels, according to some example embodiments that permit fluid flow through the flood space 151, the foam components 159 may include an internal open channel to create a flow void 161. Such an internal open channel may be needed because the form fit of the foam components 159 may otherwise prevent fluid flow through the flood space 151.

As mentioned above, according to some example embodiments, the distribution of the foam components 159 may be determined relative to the center longitudinal axis 101. As such, the aggregate buoyancy that is generated by the foam components 159 may be aligned with the axis 101. In this manner, the modularity of the floodable shell 158 can be maintained with respect to the buoyancy contribution to the submersible vehicle 100. Moreover, due to the positioning of the foam components 159 within the body or fuselage of the submersible vehicle 100, it avoids any impact on maneuverability relative to externally-positioned buoyance compensation components. In this regard, the foam components 159 are subjected to external, at-depth pressures, but are still positioned within the cylindrical body of the submersible vehicle 100.

According to some example embodiments, a method for operating a submersible vehicle, such as the submersible vehicle 100, is provided by the flowchart of FIG. 13. In this regard, the submersible vehicle may comprise a pressure vessel coupled to a floodable actuator vessel. In consideration of that context, the example method may comprise, at 1300, flooding an interior flood space of a floodable shell of the floodable actuator vessel with a fluid due to submersion of the submersible vehicle into the fluid. In this regard, the fluid may flood into the interior flood space via a plurality of flood openings in the floodable shell. Further, a plurality of actuators may be disposed within the interior flood space. The plurality of actuators may be affixed to a plurality of external fins that extend from an exterior surface of the floodable shell. The example method may further comprise, at 1310, preventing intrusion of the fluid into an interior cargo compartment of a pressure shell of the pressure vessel despite submersion of the submersible vehicle into the fluid. The interior cargo compartment may be an air-filled compartment. Additionally, a controller for the submersible vehicle may be disposed within the interior cargo compartment. The example method may further comprise, at 1320, controlling, via the controller, an output of electrical signals to the plurality of actuators and a motor of a propulsion assembly to maneuver the submersible vehicle while the interior flood space of the floodable shell is flooded and the interior cargo compartment is air-filled. Additionally, according to some example embodiments, the example method may further comprise maintaining level buoyancy of the submersible vehicle due to foam disposed within the interior flood space.

The embodiments presented herein are provided as examples and therefore the disclosure is not to be limited to the specific embodiments disclosed. Modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, different combinations of elements and/or functions may be used to form alternative embodiments. In this regard, for example, different combinations of elements and/or functions other than those explicitly described above are also contemplated. In cases where advantages, benefits or solutions to problems are described herein, it should be appreciated that such advantages, benefits and/or solutions may be applicable to some example embodiments, but not necessarily all example embodiments. Thus, any advantages, benefits or solutions described herein should not be thought of as being critical, required or essential to all embodiments.

SUBMERSIBLE VEHICLE WITH A FLOODABLE ACTUATOR VESSEL

Information

Publication Number

Date Filed

Date Published

Inventors

Original Assignees

CPC

International Classifications

Abstract

Description

Claims

CROSS-REFERENCE TO RELATED APPLICATIONS

Provisional Applications (1)