Vector control assembly for submersible vehicles.

Abstract

A submersible vehicle (10) is provided that is capable of six degrees of freedom without the use of external control surfaces, using only two thrusters in combination, each of which includes a number of flow tubes (28) that can be selectively opened and closed to various degrees, thereby enabling six degrees of freedom in both control and propulsion.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is related to and claims priority to U.S. Provisional Patent Application No. 63 / 246,325, filed September 21, 2021, the entire contents of which are incorporated herein by reference.

[0002] This disclosure relates to a directional control system for submersible vehicles, such as remotely operated vehicles (ROVs) or autonomous underwater vehicles (AUVs), operated by an umbilical tether, radio control, optical control, or acoustic control. More specifically, this disclosure relates to a control system for a submersible vehicle that uses two thrusters to achieve six degrees of freedom in position and motion control without the use of external control surfaces. This disclosure can achieve these functions while improving the inherent stability and other desired diving control capabilities of the submersible vehicle. [Background technology]

[0003] Submersible vehicles, such as autonomous underwater vehicles (AUVs) and remotely operated vehicles (ROVs), are propelled through the water column by a single thruster assembly. The thruster assembly typically has one of various types of electric or fuel-powered motors that power a drive shaft, which rotates a propeller attached to the motor. There are various types of shrouds, conduits, or exposed propeller assemblies that direct the thrust generated by the propeller along the X-axis of a fixed Earth coordinate system to provide forward or reverse motion. Directional control of the submersible vehicle is typically achieved by three or more exposed external control surfaces. These exposed external control surfaces, or "control surfaces," operate independently or in coordination with one another. The movement of the control surfaces creates resistance to the movement of the submersible body through the water column, forcing the submersible to turn with three degrees of freedom via yaw (submersible moves left and right on the X axis), pitch (submersible moves up and down on the Y axis), and roll (submersible's rotation angle away from the centerline on the X axis), as shown in Figure 1.

[0004] Currently used submersible control systems suffer from many design flaws and shortcomings. For example, while this basic design method is used by various autonomous underwater vehicles (AUVs) for underwater movement and directional control, such designs fail to address the challenges associated with the various environments and desired position control that may be encountered during oceanographic surveys.

[0005] Submersibles that typically generate thrust and / or position control from the rear of the hull are inherently unstable, requiring constant adjustments by the position control system to maintain the desired course. Furthermore, hull shapes other than spherical create moments when the submersible tilts in an inviscid fluid. While d'Alembert's paradox predicts that the net force will be zero, the moment is not necessarily zero. This so-called Munk moment results from the asymmetric location of the stagnation point, where pressure is highest forward of the body (decelerating flow) and lowest aft (accelerating flow). The Munk moment is always destabilizing, as it tends to rotate the submersible perpendicular to the water flow. This effect can be countered by submersible designs that utilize forward (bow) control surfaces, forward thrusters that can apply thrust to counter the Munk moment, or a combination of such design elements. As the length and cross-sectional area of ​​a submersible increase, the Munk moment forces on the submersible become more significant, requiring more effort from the control system to maintain the desired position. Some submersibles account for Munk moment forces by combining five or more thrusters with two sets of control surfaces to achieve six degrees of freedom. Additional control surfaces at the forward (bow) section minimize the Munk moment on the hull and stabilize forward motion along the X-axis.

[0006] Controlling the geographic position of a submersible of this design type requires a minimum forward or reverse motion (speed) along the X-axis of the submersible to induce fluid flow on the control surfaces and maintain the desired geographic position along all three control axes. Depending on several factors, including the size and type of control surfaces, the mass and shape of the individual submersible relative to water resistance, ocean currents, or other dynamic forces that may affect the submersible's position, such as surface waves and surface wind, the submersible must maintain a certain minimum forward motion to maintain control of its geographic position. If the forward motion of the submersible falls below this minimum, the submersible will lose position control and deviate from the desired course and position, or experience other undesirable motions, such as loss of pitch, roll, or yaw. Avoiding such loss-of-control conditions is important for accurately controlling the submersible's position, as well as for maintaining the stability of the submersible to ensure a stable platform for the data-gathering sensors and observation equipment used during the survey.

[0007] Furthermore, if a submersible of this design type encounters currents along the X-axis (surge), Y-axis (sway), or Z-axis (heave), and the currents exceed the minimum forward motion required to maintain directional control of the submersible as it moves downstream along the X-axis, the submersible design will not be suitable for maintaining control of its geographic position against such forces. If the programmed optimum forward survey speed for a given submersible is 4 km / h, and the submersible requires a minimum forward speed of 3 km / h to maintain position control, and the current is 2 km / h, then the submersible's speed on land will be 6 km / h. The submersible will attempt to reduce its forward speed to maintain its programmed surface survey speed of 4 km / h. As a result of that slowdown in forward motion, the submersible will move downstream at 4 km / h on land, but only 2 km / h in the water column, and will not have enough forward motion to achieve the minimum 3 km / h speed in the water column required to maintain position control.

[0008] Another example is a submersible moving upstream along the X-axis in an ocean current. If the ocean current exceeds the submersible's maximum forward motion capability, the submersible will lose directional control. If the submersible's maximum forward survey speed is 4 km / h, its minimum position control speed is 3 km / h, and the ocean current is 2 km / h, the submersible will not be able to achieve the minimum forward motion of 3 km / h to meet the survey speed, and it may lose its ability to maintain directional control.

[0009] Furthermore, if a submersible is moving at survey speed along the X axis but encounters an ocean current along the Y axis that exceeds the submersible's ability to maintain positional control of its heading along the X axis, the submersible may be unable to maintain its geographic position along the X axis, or may experience excessive pitching against the current in order to maintain its X axis position, resulting in degradation of survey data, reduced movement efficiency, or even loss of positional control.

[0010] Furthermore, current submersible vehicle designs are unable to perform some desired position control maneuvers. Such desired position control maneuvers may include: (1) Maintain position control along both directions of the X-axis from 0 km / h to maximum speed. (2) Maintaining position control along both directions of the Y axis from 0 km / h to maximum speed. (3) Maintaining position control along both Z-axis directions from 0 km / h to maximum speed. (4) Maintain position control along both Z-axis directions at any pitching degree from 0 km / h to maximum speed.

[0011] The ability of an undersea marine vessel, such as an autonomous underwater vehicle (AUV), to maintain a speed of 0 km / h on all three axes and maintain any desired position with six degrees of freedom along three axes of position control in a dynamic environment is commonly referred to as "station keeping" or "parking." Current submersible designs that use five or fewer thrusters for position keeping are unable to control station keeping along all three axes while controlling the position of the submersible in six degrees of freedom. Current submersible designs that use five or more thrusters include: (1) An autonomous underwater vehicle (AUV) that uses 12 thrusters to achieve six degrees of freedom of position control. (2) An autonomous underwater vehicle (AUV) that uses eight thrusters and articulated body segments to achieve six degrees of freedom of position control. (3) A hovering autonomous underwater vehicle (HAUV) that uses five thrusters to achieve six degrees of freedom of position control. (4) An autonomous underwater vehicle (AUV) that utilizes a combination of five thrusters and two sets of control surfaces to achieve six degrees of freedom of position control. The forward (bow) control surfaces are used to minimize the Munk moment on the hull, helping to stabilize forward motion along the X axis.

[0012] The above-mentioned prior art attempts have not met the needs of the industry. There is a significant need in the industry for submersible propulsion and systems that utilize as few thruster combinations as possible to improve power efficiency and simplify control, and that are capable of achieving six degrees of freedom without the use of external control surfaces. The prior art documents relevant to the invention of this application are as follows (including documents cited in the international phase after the international filing date and documents cited when the application entered the national phase in other countries). (Prior art document) (Patent document) (Patent Document 1) International Publication No. 2017 / 109148 (Patent Document 2) U.S. Patent Application Publication No. 2015 / 0027125 (Patent Document 3) U.S. Patent Application Publication No. 2003 / 0167998 Summary of the Invention [Means for solving the problem]

[0013] The present disclosure provides an improved submersible propulsion and position control system that maintains the advantages of the prior art while achieving six degrees of freedom of position control using only a combination of two thrusters and two thrust vector control assemblies, without the use of external control surfaces.

[0014] One objective of the present disclosure is to directly counteract Munk moments and improve the inherent stability of a submersible by simultaneously providing propulsion and position control at both the bow (forward) and stern (aft) of the submersible.

[0015] Another object of the present disclosure includes improving other desired submersible vehicle control capabilities by improving bow position control while the vehicle is moving on the surface in all sea conditions, thereby providing more stable control of the submersible vehicle on the surface, and optimizing visual position and communication with the submersible vehicle on the surface.

[0016] A further object of the present disclosure includes control of the submersible's bow or stern thrusters and position control assembly independently of one another to provide redundant position control for self-rescue of the submersible in the event of failure of one of the thrusters or the position control assembly.

[0017] Yet another object of the present disclosure includes reducing, or in some cases eliminating, protrusions typical of other submersible vehicle designs, such as external control surfaces and exposed or partially exposed thruster assemblies or propellers, thereby reducing drag, improving propulsive efficiency, and reducing the likelihood of the submersible vehicle becoming entangled in debris, structures, marine organic matter, or their surfaces.

[0018] Further objectives of the present disclosure include the elimination of external control surfaces and exposed or partially exposed thruster propellers to reduce the potential for damage to the submersible during survey operations, launch and recovery from a support vessel, fixed platform, or shore, or during routine submersible operation.

[0019] Other objects of the present disclosure are detailed throughout the disclosure, drawings, and claims. [Brief explanation of the drawings]

[0020] The novel elements which are characteristic of the present disclosure are set forth in the appended claims, however, the preferred embodiments of the present disclosure, together with further objects and attendant advantages thereof, will best be understood by reference to the following detailed description taken in conjunction with the accompanying drawings. [Figure 1] FIG. 1 shows the body-fixed frame coordinate system and the Earth-fixed frame coordinate system. [Figure 2] Figure 2 shows the six degrees of freedom of the fixed frame coordinate system. [Figure 3A] FIG. 3A is a perspective view of a submersible vehicle employing the vector control assembly of the present disclosure, showing the antenna in an extended position. [Figure 3B] FIG. 3B is a perspective view of a submersible vehicle employing the vector control assembly of the present disclosure, showing the antenna in a folded, stowed position. [Figure 4] FIG. 4 is an exploded view of the bow vector control assembly of the present disclosure (the stern vector control assembly is identical). [Figure 5] FIG. 5 is an exploded close-up view of the bow vector control assembly of the present disclosure (the stern vector control assembly is identical). [Figure 6] FIG. 6 is a perspective view of a thruster assembly. [Figure 7] FIG. 7 is a front perspective view of a flow tube housing according to the present disclosure. [Figure 8] FIG. 8 is a rear perspective view of a flow tube housing according to the present disclosure. [Figure 9] FIG. 9 is a side perspective view of a control valve assembly with the flow tube housing removed of the present disclosure. [Figure 10] FIG. 10 is a side view of a control valve assembly with the flow tube housing removed of the present disclosure. [Figure 11] FIG. 11 is a perspective view of a control valve assembly of the present disclosure. [Figure 12] FIG. 12 is a side view of a control valve assembly of the present disclosure. [Figure 13] FIG. 13 is a cross-sectional view of the thruster assembly of the present disclosure taken along line 13-13 of FIG. [Figure 14] FIG. 14 is a diagram of the flow tube flow path with the control valve in the neutral position. [Figure 15] FIG. 15 is a view of the flow tube flow path with the control valve in the vertical thrust position. [Figure 16] FIG. 16 is a view of the flow tube flow path with the control valve in the lateral thrust position. [Figure 17] FIG. 17 is a perspective view showing details of the water flow through the thruster of the present disclosure. [Figure 18] FIG. 18 is an end view showing details of the water flow through the thruster of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0021] Certain exemplary embodiments will be described to provide a general understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments, and that the scope of the present disclosure is defined only by the claims. Features shown or described in connection with one exemplary embodiment may be combined with features of other embodiments. Such modifications and variations are intended to be included within the scope of the present disclosure. Furthermore, this disclosure does not necessarily describe in full detail every feature of each like-numbered component within a particular embodiment, since like-numbered components in embodiments typically have similar features. Additionally, to the extent that linear or circular dimensions are used in describing the disclosed systems, devices, and methods, such dimensions are not intended to limit the types of shapes that can be used with the systems, devices, and methods. Those skilled in the art will recognize that equivalents to such linear and circular dimensions can be readily determined for any geometric shape. Furthermore, to the extent that directional terms such as top, bottom, above, or below are used, these terms are not intended to limit the systems, devices, and methods disclosed herein. Those skilled in the art will recognize that these terms are merely relative to the systems and devices described and are not general. While this disclosure refers to an autonomous submersible vehicle, those skilled in the art will understand that other submersible vehicles or underwater vehicles generally may be used. Furthermore, while reference is made to water, those skilled in the art will understand that the submersible vehicles described herein may be used in other fluids.

[0022] The present disclosure is generally shown and illustrated in FIGS. 3-12, and operational aspects are disclosed in FIGS. 13-18. The present disclosure provides a propulsion and directional control system for a submersible vehicle, such as an autonomous underwater vehicle (AUV) or remotely operated vehicle (ROV), but is equally applicable to any submersible vehicle operating in a given fluid medium. With reference to FIGS. 1 and 2, a coordinate reference frame is provided for illustrative purposes. According to the present disclosure, the submersible vehicle, as shown in FIG. 2, can achieve six degrees of freedom, i.e., linear controlled motion along the x-, y-, and z-axes, and rotation, defined as pitch, yaw, and roll, utilizing only a combination of two thrusters without the use of externally mounted control surfaces.

[0023] As shown in FIGS. 3A and 3B, the submersible vehicle 10 has a body 12 that can have a tubular or capsule-like shape. FIG. 3A shows the antenna mast 46 in an extended position, and FIG. 3B shows the antenna mast 46 pivoted to nest within a seat 49. The submersible vehicle 10 includes one bow thruster 14a and one stern thruster 14b, which are similarly configured and operate, simply reversed for attachment to the end of the submersible vehicle body. Therefore, the remainder of this disclosure will discuss in detail the thruster assembly 14, which applies equally to either the bow thruster 14a or the stern thruster 14b. In some embodiments, portions of the submersible vehicle can be 3D printed or additively manufactured. In other embodiments, portions can be manufactured using machining, casting, molding, or any other known manufacturing techniques, or a combination thereof. Each of the bow and stern thrusters may have an inlet portion and an outlet portion, as described further below. The body section 12 of the submersible vehicle 10 may house a battery section and an electronics section. The battery section may house a plurality of batteries capable of powering the bow thruster 14 a, the stern thruster 14 b, and any electronics used on the submersible vehicle 10. The electronics section may house any number of sensors, cameras, communication modules, computing equipment, and other electronics necessary to control the various systems on the submersible vehicle.

[0024] Referring now to FIG. 4 , the submersible vehicle 10 is illustrated including an exploded view of the body 12 and thruster 14, showing the fluid flow thruster 16 and vector control assembly 18. The propulsion vector control assembly may typically consist of a single axial fluid flow thruster 16 axially centered about the vehicle's X-axis. In the illustrated embodiment, one exemplary fluid flow thruster 16 is shown as a rim-driven thruster type design, although a conventional shaft-driven propeller thruster type could also be used. The thruster 14 may take in water from the bow or stern through an inlet 20 in a shroud 22. The water is then channeled into the vector control assembly 18, which is disposed within a vector control shroud 24, as described in detail below. A gasketed clamping ring 26 provides a rigid and watertight interconnection between the body 12, the vector control shroud 24, which serves as an enclosure for the vector control assembly 18, and the shroud 22, which serves as an enclosure for the axial fluid flow thruster 16.

[0025] Figure 5 shows an enlarged view of the thruster 14. The axial fluid flow thruster 16 is disposed within the shroud 22, drawing in water through an inlet 20 and directing it outward into the vector control shroud 24. The water then enters four independent flow tubes 28, which are axially spaced apart within the vector control shroud 24 and circumferentially oriented at 45°, 135°, 225°, and 315° about the x-axis. Each flow tube 28 includes a damper assembly 30 that can restrict and adjust the flow of water through that flow tube 28 independently of the other flow tubes. The damper assembly 30 adjusts the flow of water exiting the vector control shroud 24; the relative angle of the water flow can be continuously varied by the damper assembly 30 between a longitudinal flow angle along the vehicle body 12 and a flow angle outward and perpendicular to the vehicle body. Servo motors 32 are used and are connected to each damper 30 via linkages that allow the rotational angle of each damper 30 to be controlled independently of one another. In some embodiments, cylindrical dampers can be used. In further embodiments, vane dampers with damper servo control, or a combination thereof, can be used. In some alternative embodiments, the angle and radial orientation of the discharge pipes are varied according to optimal efficiency derived from fluid models, full-scale mock-up testing, or task-specific desired performance. It is important that each discharge pipe at the bow and stern includes an independently controlled damper assembly that can slow or stop fluid flow through each pipe.

[0026] In FIG. 6, one exemplary fluid flow thruster 16 is shown as a rim-driven thruster type design, although conventional shaft-driven propeller thruster types could also be used.

[0027] 7 and 8 show detailed views of the vector control shroud 24. The vector control shroud 24 is seen to include an inlet port 34 disposed aft of the fluid-flow thruster 16 for receiving and directing the water flow from the thruster. The water flow at the inlet port 34 flows into a plurality of inlet ends 28a of the flow tubes 28 through which it passes to corresponding outlet ends 28b. A valve seat 36 is provided within the flow tubes 28 for receiving and retaining the damper 30 therein. The recess 38 is seen to receive the linkage of the servo motor 32 that controls the rotational direction of the damper 30.

[0028] Figures 9-12 provide detailed views of the vector control assembly 18 in a fully assembled position, with the vector control shroud 24 removed for clarity. The propulsion control dampers 30 are water flow restriction / direction devices that partially restrict, redirect, and adjust the volume, velocity, and lateral direction of water flow through each flow tube 28. The control dampers 30 are rotatably disposed within each corresponding flow tube 28 within the vector control shroud 24. Rotation of the control dampers 30 is accomplished by a mechanical linkage 40 that engages and controls the output shafts of high-torque servo motors 32 attached to an electronic control module 42. The dampers 30 operate as a type of valve and may be cylindrical, vane, or other types to apply different propulsion / flow rates. Each servo motor 32 is independently controlled by commands from the vehicle's autonomous navigation computer and / or remotely controlled directly by the vehicle's operator. In the illustrated embodiment, the submersible vehicle may include either a bow vector control assembly, a stern vector control assembly, or both, as described above in FIGS. 3-12 (with particular reference to FIGS. 13-18). The bow vector assembly may include a forward-facing bow thruster inlet 22 in fluid communication with the axial fluid flow thruster 16. Downstream of the axial fluid flow thruster 16, four outlet tubes 28 may be circumferentially disposed, as described above. The outlet tubes 28 generally face axially downstream and radially outward to direct the fluid flow. Each of the four outlet tubes 28 includes an independently actuable damper 30 that can restrict and redirect the water flow 44 through the corresponding outlet tube 28. Fluid or water is drawn into the bow inlet by the axial fluid flow thruster and then selectively expelled from the outlet tube by opening or closing the outlet tube. Independent adjustment of each damper allows for continuous variation of the relative volume and direction of fluid flow between longitudinal and lateral flows, thereby adjusting the imbalance between the fluid flows exiting the four outlet pipes 28 to produce linear, lateral, and rolling motion of the submersible.The bow vector control assembly, in conjunction with the stern vector control assembly at the rear of the submersible, allows for adjustment of the eight available dampers to induce pitch and yaw, which in turn allows the submersible to rest or hover in a fixed stationary neutral buoyant position.

[0029] A mast 46 is provided for remote communication with the submersible vehicle. The mast 46 serves as a connection point for a radio antenna or umbilical tether, enabling an electronic interconnection for control and data transfer between the submersible vehicle and a remote control center. The mast 46 can be fixed or retractable to reduce turbulence while the submersible vehicle is operating below the surface. For example, the mast / antenna 46 is preferably pivotally connected to the body 12 about a pivot point 47, as shown in Figures 3A and 3B above. Figure 3A shows the antenna mast 46 in an extended position, while Figure 3B shows the antenna mast 46 pivoted to nest within a seat 49.

[0030] Importantly, adjusting the water flow or thrust through the damper assemblies allows for unidirectional control of the submersible's position in all three fixed frame coordinates. Note that each discharge pipe includes a corresponding damper assembly. For example, partially closing the two dampers on the upper side of the assembly (the 45° and 315° thruster outlets) to reduce flow and thrust controls the bow's orientation and velocity while moving forward, causing the submersible to assume a bow-up position. As a further example, partially closing the two bow dampers on the lower side of the assembly (the 135° and 225° thruster outlets) to reduce flow and thrust causes the submersible to assume a bow-down position. Changing the position of each damper relative to the discharge pipes changes both the volume and velocity of water expelled from each discharge pipe, thereby changing the amount of measurable thrust generated by the discharge pipe. The relative orientation of each damper, e.g., the degree to which it is open or closed, increases or decreases the submersible's thrust, which in turn affects its orientation and / or velocity through the water column.

[0031] In another use case, if the two dampers on the port side of the assembly (the 45° and 135° thruster outlets) are partially closed to reduce flow and thrust, the submersible will yaw to port. Similarly, if the two dampers on the starboard side of the assembly (the 225° and 315° thruster outlets) are partially closed to reduce flow and thrust, the submersible will yaw to starboard. In this example, if the stern thruster is providing thrust in the same direction as the bow, the bow damper can be partially closed and the stern damper can be fully open. Alternatively, for this particular control maneuver, the bow damper can be fully closed and not used.

[0032] The submersible can function in several modes: 1. Bow-only forward: In this mode, forward propulsion and position control along the X axis are three-axis directional control only, and the stern is not utilized. 2. Bow-and-stern forward: In this mode, translational propulsion along the X axis is generated by both the bow and stern (the stern can take in water through a control damper in the open position and expel water through the assembly's "intake," providing propulsion in the same direction along the X axis as the bow assembly), with the bow providing three-axis directional control. 3. Bow-and-stern six-axis control: In this mode, both the bow and stern assemblies take in water through thruster inlets and expel water through dampers, allowing propulsion to be used to keep the submersible in a "parked" position or to move the submersible in any of the six control axes. The bow and stern assemblies can provide propulsion to each other to maintain a desired position. For example, if the bow section reduces thrust by decreasing the amount of water flowing from the thruster motor (reducing the motor's revolutions per minute (rpm)) without changing the position of the bow damper, the aft section will generate more thrust than the bow section, causing the submersible to move aft along the X-axis. 4. Reverse Motion by the Aft Section: In this configuration, the aft section can provide propulsion and three-axis directional control in the direction opposite to the submersible's forward direction along the X-axis. This configuration can be used for self-rescue, for example, if the bow section fails, if the submersible becomes stuck in an artificial object or rock and needs to reverse along the X-axis, to reverse along the X-axis at the surface while recovering the submersible, or to avoid a collision.

[0033] The forward motion of the submersible along the X-axis can be controlled by synchronizing the opening and closing of the four dampers at the bow and matching the opening and closing ratio of each damper. Furthermore, by changing the revolutions per minute (rpm) of the thruster motor, the water volume / flow velocity can be changed and the forward motion can be controlled.

[0034] By implementing two vector control assemblies at the bow and stern, positioned in opposite directions, as shown in Figures 3A and 3B, the stern assembly can control the position and movement of the submersible in three axes of control and one direction of movement. The two vector control assemblies, one at the bow and one at the stern, can cooperate to provide six degrees of freedom of position control for the submersible. The vector control assemblies may be modular and interchangeable with other vector control assemblies, with the understanding that if the bow assembly is used instead of the stern assembly, the thruster propellers on the bow assembly must be changed to ones of opposite pitch.

[0035] Additionally, by aligning the thruster outlet with the water flow inlet and vice versa, it is possible to reverse the direction of water flow through the stern vector control assembly, allowing the bow vector control assembly to perform all position control of the submersible, while the stern vector control assembly uses only forward thrust to provide unidirectional three-axis control of the submersible, as shown in Figures 3A and 3B. The same motion can be transposed from stern to bow, allowing the submersible to perform position control and motion (forward speed) control in either direction with the same efficiency and position control. By matching the revolutions per minute (RPM) of the bow and stern thrusters, the rotational torque of the submersible along the X-axis is canceled by the counter-rotating rim-driven thrusters. A rim-driven thruster can be defined as a motor / thruster combination in which the propeller is mounted directly to the rotating portion of the motor assembly. The motor assembly utilizes a "rim" armature with fixedly attached propeller blades, rather than the armature of a conventional electric motor. The rim-driven thruster design offers several advantages for marine applications, including the elimination of a watertight seal for the shaft, crush resistance, the ability to operate at any water depth, and the ability to generate more torque (surface power) at lower RPMs than conventional shaft-driven motors. Rim-driven thrusters also eliminate the need for an armature shaft / drive shaft assembly, making them less susceptible to debris such as fishing line and seaweed. As described above and illustrated, rim-driven thrusters are used to provide water propulsion for vector control assemblies. While other conventional motor / propeller combinations can be used in conjunction with damper assemblies, the illustrated embodiment utilizes a rim-driven thruster due to the advantages discussed above.

[0036] Those skilled in the art will understand that various modifications and changes can be made to the illustrated embodiments without departing from the spirit of the present disclosure, and all such modifications and changes are intended to be covered by the appended claims.

Claims

1. A submarine, a main body; at least one thruster assembly disposed at one end of the body, The entrance and a fluid flow thruster; 1. A vector control assembly comprising: a plurality of flow tubes for directing fluid flow from the fluid flow thruster; an independently adjustable damper disposed within each of the plurality of flow tubes; the vector control assembly, the at least one thruster assembly comprising: and the adjustable damper is cylindrical; wherein the rate and direction of fluid flow through the plurality of flow tubes is independently controlled by independently adjusting each of the adjustable dampers. Submersible.

2. 2. The submersible vehicle of claim 1, wherein the fluid flow thruster is a rim-driven thruster.

3. 2. The submersible vehicle of claim 1, wherein the fluid flow thruster is a shaft-driven propeller.

4. The submersible vessel of claim 1 further comprising: A plurality of servo motors are provided. each of the plurality of servo motors is independently controllable and interconnected with one of the adjustable dampers via a linkage to control the rotational position of each of the adjustable dampers.

5. 10. The submersible vehicle of claim 1, wherein the submersible vehicle has no external control surfaces.

6. 2. The submersible vehicle of claim 1, wherein the at least one thruster assembly is a two-thruster assembly consisting of a forward thruster assembly disposed at a first end of the body portion and an aft thruster assembly disposed at an opposite second end of the body portion.

7. 7. The submersible vehicle of claim 6, wherein six degrees of freedom of position control is achieved solely by moving the forward thruster assembly and the aft thruster assembly relative to one another.

8. A submarine, a main body having a forward end and a rearward end opposite the forward end; a forward thruster assembly disposed at the forward end of the body portion, The entrance and a fluid flow thruster; 1. A vector control assembly comprising: a plurality of flow tubes for directing fluid flow from the fluid flow thruster; an independently adjustable damper disposed within each of the plurality of flow tubes; the vector control assembly, the forward thruster assembly including: an aft thruster assembly disposed at the aft end of the body portion, The entrance and a fluid flow thruster; 1. A vector control assembly comprising: a plurality of flow tubes for directing fluid flow from the fluid flow thruster; an independently adjustable damper disposed within each of the plurality of flow tubes; the vector control assembly, the aft thruster assembly including: and the adjustable damper is cylindrical; wherein the rate and direction of fluid flow through the plurality of flow tubes is independently controlled by independently adjusting each of the adjustable dampers. Submersible.

9. 9. The submersible vehicle of claim 8, wherein the fluid flow thruster is a rim-driven thruster.

10. 9. The submersible vehicle of claim 8, wherein the fluid flow thruster is a shaft-driven propeller.

11. The submersible vessel according to claim 8, further comprising: A plurality of servo motors are provided. each of the plurality of servo motors is independently controllable and interconnected with one of the adjustable dampers via a linkage to control the rotational position of each of the adjustable dampers.

12. 9. The submersible vehicle of claim 8, wherein the submersible vehicle has no external control surfaces.

13. 9. The submersible vehicle of claim 8, wherein six degrees of freedom of position control is achieved solely by moving the forward thruster assembly and the aft thruster assembly relative to one another.

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