WO1990011927A1

WO1990011927A1 - Submersible vehicle

Info

Publication number: WO1990011927A1
Application number: PCT/AU1990/000133
Authority: WO
Inventors: Martin Renilson; James Milton Rigney
Original assignee: Simpson, Phillip, Bradley
Priority date: 1989-04-05
Filing date: 1990-04-05
Publication date: 1990-10-18

Abstract

An unmanned submersible vehicle (1) for carrying oceanograpby equipment, the vehicle (1) being towed under water by a surface ship. The vehicle (1) includes an elongate body (2) on which the equipment can be carried and directional control means (7, 15) mounted on the body (2) for vertically shifting the vehicle (1) during travel in a forward direction through water. The control means (7, 15) includes an elongate control wing (7) extending in a longitudinal direction above and across the body (2). Control wing (7) projects downwardly about sides of the body (2). Control wing (7) has a leading edge (11) and is angled laterally downwardly toward the leading edge (11) at an angle of attack Υ.

Description

SUBMERSIBLE VEHICLE This invention relates generally to a submersible vehicle, and in particular to an unmanned submersible vehicle towed under water by a water surface ship. The vehicle is applicable as a stable platform for carrying equipment conducting oceanography studies and operations, such as cameras, survey equipment, seismic wave transmission sources, receivers and other measuring, sensing, surveying and gathering equipment, and work performing and deployment tools and equipment. It will be convenient to hereinafter describe the invention in relation to this exemplary application, although it is to be appreciated that the invention is not limited to that application.

Various unmanned vehicles have been developed for performing underwater functions, particularly such functions that cannot be readily carried out by human divers. One such vehicle is disclosed in Australian patent application 76647/87 and includes a body or frame on which the oceanography equipment can be carried, the body being connectable to an ocean surface ship through a tow line for submerged towing. Directional control members are movably mounted on the body and are remotely actuable in order to laterally and vertically shift the vehicle, relatively to its forward direction of towed movement, and thereby "steer" the vehicle while under tow.

Although this and other vehicles can perform tasks reasonably satisfactorily, sometimes their movement through the water can be difficult to accurately control. Precise movement, positioning and stabilising can be particularly important in many vehicle uses such as during operation of 90/11927

on-board cameras and manipulation of working tools performing precision tasks. It is recognised that there are many uncontrollable external factors adversely influencing vehicle control, including water currents acting on the submersed vehicle as well as the surface ship and tow line. However, many present vehicles in part lack controllability due to their own poor hydrodynamic design and construction.

It is an object of the present invention to provide a submersible vehicle having improved design characteristics and, in consequence, alleviate the foregoing control difficulties of previous vehicles.

According to the present invention, there is provided a submersible vehicle for carrying oceanography equipment including: an elongate body on which the equipment can be carried; and, directional control means mounted on the body for vertically shifting the vehicle during travel in a forward direction through water, the control means including an elongate control wing extending in a longitudinal direction above and across the body, and projecting downwardly about sides of the body, the control wing having a leading edge and being angled laterally downwardly toward the leading edge.

This invention is disclosed herein with reference to the vehicle in a normal horizontal use orientation and terms such as "lateral", "downward" and "vertical" should be construed in the light of this orientation. However, it is to be appreciated that other orientations may be equally possible and that consequential changes in terms such as those above may be required in the light of those other orientations for a proper and complete understanding of the invention. Preferably, the control wing has a pair of wing sections. Each wing section preferably extends in an opposite longitudinal direction from over the body and is angled downwardly from over the body. In one embodiment, those wing sections extend from a common transverse wing apex extending longitudinally of the body. Thus, in this embodiment the control wing has a generally inverted V profile.

Preferably, the control wing is angled laterally downwardly up to about 10° from a horizontal plane.

Preferably, the leading edge of the control wing curves rearwardly at least adjacent outer end regions of the control wing.

Preferably, the control wing has a trailing edge spaced from the leading edge. Moreover each wing section preferably has opposed upper and lower planing surfaces. Each upper planing surface is preferably substantially flat. Each lower planing surface preferably tapers laterally of the wing section toward the trailing edge. The upper and lower planing surfaces also preferably taper longitudinally of each wing section toward an outer end region thereof. Preferably, the control wing is located at least substantially forwardly of a longitudinal mid point of the elongate body, having regard to a direction of forward travel of the vehicle.

The vehicle is preferably constructed and arranged so that, when at rest in water, it has a center of pressure and a center of gravity positioned on a common vertical balance line so that the vehicle is in a horizontal balanced orientation.

The vehicle is preferably towable under water. To that end, the vehicle preferably further includes a connection member to which a tow line is connectable. The connection member being positioned above the control wing and toward the leading edge thereof. This connection member is preferably positioned so that the tow line is connectable thereto on the vertical balance line. Preferably, the control means further includes a control tail fixed to and upstanding from the elongate body at a rear end region thereof. That control means preferably further includes a pair of control elevators projecting laterally one from each side of the tail and pivotable about a common horizontal axis located toward a leading edge of the control elevators.

The following description refers to a preferred embodiment of the submersible vehicle of the present invention. To facilitate an understanding of the invention, reference is made in the description to the accompanying drawings where the vehicle is illustrated in that preferred embodiment. It is to be understood that the vehicle is not limited to the preferred embodiment as hereinafter described and as illustrated in the drawings. In the drawings:

Fig. 1 is a perspective view of a submersible vehicle according to a preferred embodiment of the present invention;

Fig. 2 is a side elevation of the vehicle of Fig. 1;

Fig. 3 is a front elevation of the vehicle of Fig. 1; Fig. 4 is a rear elevation of the vehicle of Fig. 1; and.

Fig. 5 is a plan and side cross-sectional views of the main control wing of the vehicle of Fig. 1.

Referring to the drawings, there is generally shown submersible vehicle 1 applicable for carrying equipment (not shown) during oceanography studies and operations. Vehicle 1 is particularly intended to provide a stable but movable platform from which the studies and operations can be conducted with the equipment.

Vehicle 1 includes elongate body 2 extending along horizontal longitudinal axis X, with spaced apart front end region 3 and rear end region 4, having regard to a forward direction of vehicle travel as indicated by arrow T. Oceanography equipment will generally be contained within or mounted on body 2. Body 2 is hydrodynamically shaped to facilitate stable movement through the water and, to that end, is conveniently streamlined in shape as shown. In this embodiment, vehicle body 2 is shaped so as to present a generally smooth and rounded outer surface 5. Body 2 is of a regular (as shown) or irregular (not shown) circular cross-sectional shape. In that regard, as shown outer surface 5 tapers longitudinally from front end region 3 to rear end region 4. That taper is generally constant. At least front end region 3 is rounded, such as into a hemi-spherical shape and, in this embodiment, conveniently both end regions 3,4 are so rounded.

Body 2 includes a frame work (not shown) and shell 6 extending over the frame work to provide outer surface 5. Body 2 is of a rigid construction.

Body 2 is composed of any suitable materials such as metal and plastics. In this embodiment, one or both of end regions 3,4 are composed of transparent material for external visibility from inside body 2. In the exemplary application, cameras and the like oceanography equipment can be conveniently located in the transparent end region(s) 3,4 for external image recording. In this embodiment, vehicle 1 has main directional control wing 7 overlying body 2 between end regions 3,4. In this embodiment, wing 7 extends over body 2 forwardly of a mid point of body 2 and overlies a substantial longitudinal extent of body 2. In this embodiment, main control wing 7 is closely spaced above body outer surface 5 and projects downwardly at the body sides to outer end regions 8 which are located at a level approximate a horizontal mid-plane M of body 2 containing longitudinal axis X. In this embodiment, these end regions 3,4 are located at a level just beneath that mid-plane M.

Main control wing 7 has a pair of mirror-image wing section 9, each extending in opposite directions from over body 2. Those wing sections 9 are juxtaposed one another over body 2, providing central transverse apex 10 extending longitudinally of body 2 and transversely of control wing 7.

Wing sections 9 are each generally planar and angled longitudinally downwardly away from transverse apex 10. Thus, main control wing 7 has an inverted V profile. The angle θ of wing sections 9 is relatively shallow and, in this embodiment, is about 10° to 15° downward from a horizontal plane.

In this embodiment, wing sections 9 provide main control wing 7 with opposed leading edge 11 and trailing edge 12 extending generally transversely of body 2. These edges 11 and 12 extend parallel to one another through apex 10 and over body 2.

In this embodiment, leading edge 11 extends rearwardly adjacent outer end regions 8. In this embodiment as shown, leading edge 11 is generally curved rearwardly at outer end regions 8. The curvature is singular (as shown) or compound (not shown) in alternative embodiments.

In this embodiment, trailing edge 12 extends forwardly adjacent outer end regions 8. In this embodiment as shown, trailing edge 12 is also generally curved rearwardly at outer end regions 8. The curvature is also singular (as shown) or compound (not shown) in alternative embodiments. In another embodiment (not shown) trailing edge 12 extends straight laterally of body 2 from apex 10 to outer end regions 8. In this embodiment, each wing section 9 of main control wing 7 has opposed upper planing surface 13 and lower planing surface 14. As best shown in Fig. 5, planing surfaces 13,14 converge toward one another adjacent leading edge 11 and trailing edge 12. Moreover, those upper and lower planing surfaces 13,14 longitudinally converge toward one another from over body 2 to outer end regions 8.

Specifically, each upper planing surface 13 is at least substantially flat. Moreover, each lower planing surface 14 curves upwardly to meet each upper planing surface 13 at leading edge 11. That curvature extends only immediately adjacent leading edge 11. Each lower planing surface 14 tapers upwardly to meet respective upper surface 13 at trailing edge 12 thereof. The taper extends over a substantial lateral extent of each lower planing surface 14 and, in this embodiment, that taper extends over at least one half of the lateral extent of each lower planing surface 14. Moroever, the taper is such that control wing 7 tends to feather to trailing edge 12.

Each lower planing surface 14 tapers constantly toward upper planing surface 13 from adjacent apex 10 to each outer end region 8. In effect, wing sections 9 tend to feather from apex 10 to outer end regions 8. In this embodiment, each upper planing surface 13 projects downwardly at an angle θ of about 15° whilst each lower planing surface 14 projects downwardly at an angle θ of about 10°.

In this embodiment, main control wing 7 is rigidly fixed to body 2. Fixing is such that control wing 7 is angled laterally downwardly in direction of travel T. Thus, control wing 7 tilts downwardly and forwardly toward leading edge 11, providing an angle of attack θ between apex 10 and horizontal. This angle of attack θ is up to about 10° and, in this embodiment, is about 7.5°. The angle of attack θ is not above about 10° because, as will become apparent hereinafter, such a steep angle can induce "stall" in the vehicle leading to uncontrolled movement.

In an alternative embodiment (not shown), control wing 7 is movable relative to body 2 in order to vary the angle of attack θ. This ability to move wing 7 may provide an advantage of improving control over the movement of vehicle 1, particularly at various vehicle travel speeds. Wing 7 is hingedly connected to body 2 for tilting. The angle of attack θ extends from between about +10° to -5°, the negative angle of tilt θ being available for use at slow vehicle speeds, with control wing 7 taking on an increasing positive angle of attack θ at higher speeds.

In this embodiment, wing sections 9 of main control wing 7 are rigidly fixed together at apex 10. In an alternative embodiment (not shown) , control wing sections 9 may be movable relative to one another, such as each wing section 9 being pivotable about an axis at apex 10. Vehicle 1 has additional direction control members 15, mounted on body 2 toward rear end region 4.

Control members 15 include control tail 16 rigidly connected to and upstanding from body 2 at rear end region 4. Although not shown a control rudder may be mounted on a trailing edge of tail 16 for pivotal movement about a vertical axis.

Control members 15 further include a pair of elevators 17 projecting laterally one from each side of control tail 16 and pivotable about a common horizontal pivot axis Z. Control elevators 17 are pivotable together (as shown) or independently (not shown). In this embodiment, elevators are pivotable through angle α of up to about 30° downwardly from a horizontal plane containing pivot axis Z. Control elevators 17 are generally rectangular shaped with opposite planing surfaces 18,19 extending between leading edge 20 and trailing edge 21 having regard to direction of travel T. Planing surfaces 18,19 are substantially flat and converge toward trailing edges 21 so that each elevator 17 tends to taper from leading edge 20 to trailing edge 21 thereof.

Although not shown vehicle 1 also includes drive means actuable to move control wing 7 (where movable) and control elevators 17, and maintain them in selected positions. That drive means is actuable so that main control wing 7 (where movable) and control elevators 17 are independently movable. The drive means includes drive motors such as piston-and-cylinder motors (hydraulically or pneumatically actuated) or electric linear actuators. In this embodiment vehicle 1 has a slight positive buoyancy, and will therefore rise, although remain at least substantially immersed, when not being moved through the water either by driving or towing. Additionally, vehicle 1 is constructed and arranged (and particularly shaped and weighted) so that centre of gravity G and centre of pressure P lie on common vertical balance line B. Line B is located forward of mid-point m, toward front end region 3 of body 2, and passes through longitudinal axis X. Control wing 7 is positioned so as to extend from adjacent mid-point m, forwardly thereof through line B. To achieve the correct buoyancy and balance, floatation material is strategically placed within body 2. With main control wing 7 positioned toward front end region 3, that floatation material is placed toward rear end region 4, and particularly in tail 16, for balance.

In this embodiment, vehicle 1 is unmanned, its operation entirely controlled from a remote location. However, it is envisaged that in an alternative embodiment (not shown) vehicle 1 could be manned with at least some if not all operations being controlled on-board.

Vehicle 1 has a pair of support skids 23 for stably supporting body 2 such as on an ocean floor during use and ship deck when not in use. Skids 23 may also act to protect body 2 and oceanography equipment mounted therein from external damage, and well as provide useful mounting points for external equipment if necessary.

In this embodiment, vehicle 1 is towed under water, although it is envisaged in an alternative embodiment (not shown) that vehicle 1 could be provided with its own propulsion means. Towing is conveniently achieved by connecting the submersible vehicle to an ocean surface ship or other driven ocean going towing vehicle (for example a submarine) (not shown) through tow line L. Tow line L is connected to vehicle 1 through connection lug 22 mounted on control wing 7. The location of connection lug 22 is selected so that the connection between vehicle 1 and tow line L lies on common vertical balance line B. This enables stable towing while permitting controlled manoeuvrability of vehicle 1,

In this embodiment, tow line L is utilised as a carrier for transmitting data between vehicle 1 and towing vehicle. That may be particularly appropriate where vehicle 1 is unmanned. In that regard, control instruction data can be supplied to the drive means and oceanography equipment, whilst research or information data can be transmitted from the oceanography equipment back to the towing vehicle. In this embodiment tow line L is an armoured impulse transmitting tow line.

As previously indicated, vehicle 1 may carry any suitable oceanography equipment. The equipment may be removably or permanently mounted within vehicle 1, with vehicle 1 and particularly body 2 being constructed to appropriately accommodate that equipment. In that regard, vehicle body 2 may be appropriately recessed to receive pieces of equipment therein so that it is generally protected by vehicle 1 and the streamline appearance of vehicle 1 is not adversely affected by the equipment. Conveniently, the oceanography equipment is operable quite independently or in coordination with vehicle movement.

In using this preferred embodiment of submersible vehicle 1, that vehicle 1 is connected to tow line L behind a surface ship. Movement of the ship through the water will tow the vehicle in a forward direction through that water. Controlled shifting of vehicle 1 vertically is achieved by pivotal movement of control elevators 17 and altering the length of tow line L played out to vehicle 1 from the surface ship.

When vehicle 1 is initially deployed into the water, its positive buoyancy causes vehicle 1 to sit in the water, longitudinal axis X lying horizontally and with control wing 7 and elevators 17 immersed. Elevators 17 are pivoted to their horizontal position at 0° angle α.

As vehicle 1 is towed with tow line L, the angle of attack θ of control wing 7 provides a resultant downward water force on wing 7 counteracting the positive buoyancy. This water force causes vehicle to move downwardly, although longitudinal axis X remains horizontal throughout downward movement. The extent of downward movement is limited to the amount of tow line L played out so that sufficient tow line L is played out until vehicle 1 reaches a desired depth. At that depth tow line L is secured and vehicle 1 is towed behind the surface ship with longitudinal axis X remaining horizontal, and vehicle 1 moving stably through the water.

When it is desired to raise vehicle 1, elevators 17 are pivoted through angle α to provide an upward water force on elevators 17. This causes vehicle 1 to tilt or dip downward at front end region 3, and thus increase the angle of attack θ beyond 10°. As a result vehicle 1 "stalls", causing it to rise in a combined upward and "backward" movement to a new depth. Return pivoting elevators 17 to 0° angle α overcomes this vehicle "stall" and enables vehicle 1 to resume a stable position in which longitudinal axis X is again horizontal. If tow line L is retrieved as vehicle 1 rises then, when vehicle 1 resumes its stable position, vehicle 1 will remain at this new depth during subsequent towing. This is appropriate where it is desired to permanently shift vehicle 1 between water depths. However, if tow line L is not retrieved then, when vehicle resumes its stable position, continued towing will again cause vehicle 1 to move downwardly to the previous depth. This may be useful in temporarily shifting vehicle 1 such as to avoid an underwater obstruction.

Finally, it is to be appreciated that various modifications and/or alterations may be made to the vehicle without departing from the ambit of the present invention as defined in the claims appended hereto.

Claims

Claims :

1. A submersible vehicle for carrying oceanography equipment including: an elongate body on which the equipment can be carried; and, directional control means mounted on the body for vertically shifting the vehicle during travel in a forward direction through water, the control means including an elongate control wing extending in a longitudinal direction above and across the body, and projecting downwardly about sides of the body, the control wing having a leading edge and being angled laterally downwardly toward the leading edge.

2. A vehicle as claimed in claim 1, wherein the control wing has a pair of wing sections, each wing section extending in opposite longitudinal directions from over the body and being angled downwardly from over the body.

3. A vehicle as claimed in claim 2, wherein the wing sections extend in opposite longitudinal directions from a common transverse wing apex extending longitudinally of the body.

4. A vehicle as claimed in claim 2 or 3, wherein the control wing has an inverted V profile, each wing section being angled downwardly between 10 and 15° from a horizontal plane.

5. A vehicle as claimed in any preceding claim, wherein the control wing is angled laterally downwardly up to about 10° from a horizontal plane.

6. A vehicle as claimed in any preceding claim, wherein the leading edge of the control wing curves rearwardly at least adjacent outer end regions of the control wing.

7. A vehicle as claimed in any preceding claim, wherein the control wing has a trailing edge spaced from the leading edge, and each wing section has opposed upper and lower planing surfaces, each upper planing surface being substantially flat and each lower planing surface tapering laterally of the wing section toward the trailing edge.

8. A vehicle as claimed in claim 7, wherein the upper and lower planing surfaces of each wing section taper longitudinally of the wing section toward an outer end region thereof.

9. A vehicle as claimed in any preceding claim, wherein the control wing is located at least substantially forwardly of a longitudinal mid point of the elongate body, having regard to a direction of forward travel of the vehicle.

10. A vehicle as claimed in any preceding claim, wherein the vehicle is towable under water and further includes a connection member to which a tow line is connectable, the connection member being positioned above the control wing and toward the leading edge thereof.

11. A vehicle as claimed in any preceding claim, wherein when at rest in water the vehicle has a center of pressure and a center of gravity positioned on a common vertical balance line so that the vehicle is in a horizontal balanced orientation.

12. A vehicle as claimed in claim 11, when appended to claim 11, wherein the connection member is positioned so that the tow line is connectable thereto on the vertical balance line.

13. A vehicle as claimed in any preceding claim, wherein the control means further includes a control tail fixed to and upstanding from the elongate body at a rear end region thereof.

14. A vehicle as claimed in claim 13, wherein the control means further includes a pair of control elevators projecting laterally one from each side of the tail and pivotable about a common horizontal axis located toward a leading edge of the control elevators.

15. A submersible vehicle for carrying oceanography equipment, substantially as hereinbefore described with reference to what is shown in the accompanying drawings.