Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
  • G01V1/00—Seismology; Seismic or acoustic prospecting or detecting
  • G01V1/38—Seismology; Seismic or acoustic prospecting or detecting specially adapted for water-covered areas
  • G01V1/3817—Positioning of seismic devices
  • G01V1/3826—Positioning of seismic devices dynamic steering, e.g. by paravanes or birds

Definitions

• the invention relates generally to towed hydrophone arrays and, more particularly, to devices for controlling the positions of towed arrays.
• Linear hydrophone arrays are towed behind submarines for sonar applications.
• Typical linear arrays are tubular in shape with a diameter no greater than a few inches.
• the arrays are payed out and retrieved by handling equipment through a small opening in the submarine.
• the handling equipment generally includes a reel for a tow cable attached to the head end of the array.
• the tow cable includes both strength members and electrical conductors for powering and communicating with electronics in the array.
• the array When towed at low speeds, the array tends to sink because of the weight of the tow cable and the array itself. When the array sinks, its aft end rides deeper than its fore end, which causes its sensor performance to suffer. Furthermore, there is a greater opportunity for the array to be damaged by collision with the sea floor or underwater obstructions. Often it is desirable to operate the array out of the wake or the acoustic shadow of the submarine. This can be achieved to some extent through submarine maneuvers, but such maneuvers may not be possible or preferred in some circumstances.
• the apparatus comprises an elongated body with an outer surface disposed about a longitudinal axis.
• the elongated body is suitable for being connected axially in line with a towed underwater cable.
• a first wing swings outward from the elongated body through a first opening formed in the outer surface; a second wing swings outward from the elongated body through a second opening formed in the outer surface opposite the first opening.
• Each of the first and second wings extends from a root to a wing tip.
• a first wing actuator which is disposed within the body and coupled to the root of the first wing, rotates the first wing on a first axis of rotation.
• the wing rotates from a stowed position within the elongated body to operational positions wherein the wing tip is outside the elongated body.
• the span of the first wing defines a first sweep angle with the longitudinal axis of the elongated body.
• a second wing actuator rotates the second wing similarly through a second sweep angle. The first and second sweep angles are independently adjustable by the first and second actuators.
• a position controller comprises a body suitable for being connected in line with a towed underwater cable and a pair of dihedral wings.
• a first dihedral wing has a wing tip that can swing outward from the body through a first slot formed in the outer surface off the body.
• a second dihedral wing has a wing tip that can swing outward from the body through a second slot formed in the outer surface.
• a position controller for a towed underwater cable comprises an elongated body suitable for being connected axially in line with a towed underwater cable.
• the elongated body has an outer surface disposed about a longitudinal axis with first and second slots through the outer surface.
• the first and second slots each include a forward segment that is oblique to the longitudinal axis and a rearward segment oblique to the forward segment.
• a first wing has a wing tip that swings outward from the elongated body through the first slot.
• a second wing has a wing tip that swings outward from the elongated body through the second slot.
• apparatus for positioning a towed underwater cable comprises an elongated body with an outer surface disposed about a longitudinal axis.
• the elongated body is suitable for being connected axially in line with a towed underwater cable.
• the outer surface is divided into a first half and a second half by a plane containing the longitudinal axis.
• the elongated body forms a first opening in the first half of the outer surface and a second opening in the second half of the outer surface.
• a first wing swings outward from the elongated body through the first opening.
• the first wing extends from a wing root along an inner wing panel to an outer wing panel terminated in a distal wing tip.
• a second wing swings outward from the elongated body through the second opening.
• the second wing extends from a wing root along an inner wing panel to an outer wing panel terminated in a distal wing tip.
• the inner wing panels of the first and second wings have chords defining a non-zero angle of attack with the longitudinal axis of the elongated body.
• apparatus for positioning a towed underwater cable comprises a body having an outer surface disposed about a longitudinal axis.
• the body is suitable for being connected axially in line with a towed underwater cable.
• the outer surface is divided into a first half and a second half by a plane containing the longitudinal axis.
• a cavity that extends to a first opening in the first half of the outer surface a second opening in the second half of the outer surface is formed in the interior of the body.
• a first wing with upper and lower airfoil surfaces swings outward from the cavity through the first opening.
• a second wing with upper and lower airfoil surfaces swings outward from the cavity through the second opening.
• the first and second wings are stacked in the cavity with the upper airfoil surface of the second wing adjacent the lower airfoil surface of the first wing.
• FIG. 1 is an isometric view of a cable positioning control device embodying features of the invention
• FIG. 2 is a side elevation view of the cable position controller of FIG. 1;
• FIG. 3 is a front isometric view, partly cut away, of the position controller of FIG. 1;
• FIG. 4 is a rear isometric view, partly cut away, of the position controller of FIG. 1;
• FIG. 5 is an enlarged oblique cross section of the position controller taken along lines
• FIGS. 6A and 6B are top plan and front elevation views of the right wing of the position controller of FIG. 1;
• FIG. 7 is a profile of the airfoil shape of the wing of FIGS. 6A and 6B;
• FIG. 8 is a front elevation view of the position controller of FIG. 1;
• FIGS. 9A-9C are isometric views of the position controller of FIG. 1 with the wings fully deployed, partially deployed, and fully retracted;
• FIG. 10 is a side elevation representation of a submarine towing an array provided with a position controller as in FIG. 1;
• FIGS. 1 IA and 1 IB are perspective views of the position controller of FIG. 1 with the wings arranged to steer left and to steer right;
• FIG. 12 is a schematic diagram of a communication and position control system usable with the position controller of FIG. 1;
• FIG. 13 is a block diagram of a position control system usable in the position controller of FIG. 1;
• FIG. 14 is an isometric view of another version of a position controller embodying features of the invention, including a retractable stabilizing weight;
• FIG. 15 is a side elevation view of the position controller of FIG. 16 with the stabilizing weight fully retracted.
• FIG. 16 is a perspective view of yet another version of depth controller embodying features of the invention, including planar wings.
• the position controller 20 comprises an elongated body, or fuselage 22, from which left and right retractable wings 24, 25 extend.
• the fuselage which includes a preferably cylindrical outer surface, or tube 26, extends in length along a central longitudinal axis 27 from a head end 28 to a tail end 29.
• the rear end of the position controller attaches to a towed array 34.
• the position controller attaches in line between the tow cable and the head of the towed array.
• the wings are retractable through slots 36, 37 opening onto the outer surface of the fuselage.
• the slots may communicate in the interior of the fuselage to define a single wing receptacle 38 through the fuselage.
• Each slot includes a forward segment 40 and an oblique rearward segment 41.
• the rearward segment is parallel to the longitudinal axis 27 of the fuselage, and the forward segment is tilted off the longitudinal axis preferably at an angle ⁇ of 11° or less, and more preferably at an angle of about 7°.
• the angle ⁇ is selected based on the performance requirements and the system parameters of the array being used. Consequently, ⁇ may even exceed 11° in some applications.
• the upward tilt of the slot from rear to front ensures a positive wing angle of attack relative to the longitudinal axis of the fuselage. In this way, even if the wings become locked through loss of power or physical damage, they will be in a position tending to move the fuselage upward under tow.
• each wing 24, 25 extends from a wing root 44, 45 to a distal wing tip 46, 47.
• the root of each wing is attached to an individual rotary actuator, which, in this example, is realized by a motorized linear actuator 48 turning a lead screw along which a nut 49 is advanced.
• a motorized linear actuator 48 turning a lead screw along which a nut 49 is advanced.
• One end of a rod 50 is received in an oversized opening in the nut, and the other end is received in a hole through the wing root.
• the linear motion of rod with the nut causes the wing to rotate about a stationary axle 51 through the wing root inward of the rod.
• the axle is supported in a support 52 mounted to a plate 53 attached to the inside of the fuselage.
• the actuators for each wing operate the same way and constitute independent actuators for each wing.
• the rod and the axle may serve as shear pins to prevent a wing stuck in an open position from damaging the submarine's array bay opening or the array handling system. Because, in this example, the two wings, like a pair of scissors, rotate on the same axle, they are offset slightly in a radial direction relative to the axis of the fuselage
• the actuators are controlled by an electronic wing control system housed in an electronics package 60 in the interior cavity 62 of the fuselage.
• the electronics package preferably includes a roll sensor 54, a wing position sensor 55, and, optionally, a depth sensor 56. (If the array includes a depth sensor, there may be no need for one in the position controller.)
• a forward port 64 formed in a front panel 66 of the fuselage admits power, signal, control, and communications conductors 68 from the tow cable into the fuselage to power and control the electronics. Some or all of the conductors pass through an aft port 70 in a rear panel 72 of the fuselage.
• One or more cable troughs extend along the length of the fuselage to guide the conductors past the actuators and around the wing receptacle.
• the nose cone is attached to a forward lip 74 of the fuselage by fasteners such as screws through holes 76 formed around the circumference of the lip.
• An O-ring or other seal on the nose cone assembly prevents sea water intrusion into the interior cavity of the fuselage.
• the outer tubular surface 26 of the fuselage serves as a strength member, bearing the tension of the towed array.
• the array is attached to the rear of the fuselage in a similar fashion as the nose cone.
• An O-ring or the like forms a watertight seal with the rear of the fuselage.
• FIGS. 6A and 6B depict a right wing 25.
• the left wing is a mirror image of the right wing.
• the wing span extends from the root 45 to the wing tip 47.
• the wing root includes a shoulder 74 with a socket 76 for the axle and the hole 77 that receives the actuator rod that drives the wing.
• the wing includes an inner panel 78 extending from the root toward the wing tip and an outer panel 80 extending from the inner panel to the wing tip.
• the two panels are oblique to each other and form a dihedral wing.
• the dihedral angle 82 matches the angle ⁇ formed by the forward and rearward segments of the wing slots.
• upper and lower airfoil surfaces 84, 85 of the exemplary wing form a cambered wing 25 with inherent lift characteristics.
• the left and right wings 24, 25 form a polyhedral wing system with dihedrals 82 between the inner panels 78 and the outer panels 80, as shown in FIG. 8 with both wings fully open.
• the two inner panels are parallel to each other and offset radially because of the radial offset of the rotary actuators.
• the position controller 20 is shown with the wings in three positions in FIGS. 9A-9C. In all three positions shown, the left and right wings are symmetrically disposed with reference to the longitudinal axis.
• the wings 24, 25 are shown fully open, each at a sweep angle 86 of 90° measured from the longitudinal axis 27.
• the fully open wings produce maximum lift at a given tow speed.
• the wings are shown partly open in FIG. 9B at sweep angles of about 30° for less lift.
• the wings are shown in a fully retracted, or stowed, position at sweep angles of 0° in FIG. 9C.
• the wings When stowed within the wing receptacle 38 in the fuselage, the upper airfoil surface of the left wing is adjacent to the lower airfoil surface of the right wing in a stacked configuration.
• the wings scissors open as required from a retracted position at a sweep angle of 0° to a fully open position at a sweep angle of 90° in this example.
• the position controller can be deployed from or reeled into a submarine 56 along with the array and the tow cable.
• the array 34 is preferably deployed as in FIG. 10 with the position controller 20 between the tow cable 30 and the array.
• the forward motion 57 of the submarine even at low speeds, pulls the position controller through the water with the wings producing lift to move the array toward the sea surface until the lift and buoyancy forces equal the weight of the deployed system.
• the tow cable will droop and the array will sag at its tail 58. Tail sag can be eliminated by attaching a second position controller to the tail.
• the array will sink at low forward speeds, as indicated by the sinking array 34'.
• the position controller may also be used to steer the towed array laterally.
• the controller when commanded, orients the wings in an asymmetrical configuration, which rolls the device.
• the wings will then be adjusted to maintain a banked condition.
• the lift vector In a banked condition, the lift vector has both a vertical and a horizontal component.
• the horizontal component steers the array 34 laterally, while the vertical component controls the depth. Because each wing 24, 25 is controlled separately by its own actuator, the sweep angle of each wing can differ from that of the other. In FIG.
• the left wing 24 is retracted at a smaller sweep angle than the right wing 25 to steer the array to the left.
• the right wing is retracted more to steer the array toward the right. In this way, the array can be secured from a position directly behind the submarine to be clear of the wake.
• FIGS. 12 and 13 An array position control system usable with the position controller of FIG. 1 is shown in FIGS. 12 and 13.
• An operator in the submarine's sonar room monitors the position of the array and adjusts depth and lateral position from a graphical user interface (GUI) 88.
• GUI graphical user interface
• Signals representing depth or wing angle settings are transmitted to the position controller 20 over the conductors 68 in the tow cable 30.
• a signal decoupler 90 between the GUI computer and the tow cable helps direct signals between the wet and dry ends of the array system and to multiplex its operation with an onboard combat system. Signals representing depth are transmitted in the opposite direction back to the workstation.
• Other signals representing depth, roll, acoustic measurements, array status, and position controller status, for example, may also be transmitted back to a computer 89 at the GUI or to the combat system.
• Other control signals and command signals may be transmitted to the position controller or the array from the GUI or from the combat system.
• FIG. 13 One version of a control for use with the position controller is shown in FIG. 13.
• the operator aboard the submarine selects a depth d or a lateral offset / at the GUI.
• the selected depth and lateral offset are input to a communication interface 92, which also receives the actual depth D from a depth sensor in the array or aboard the position controller.
• the communication interface outputs a depth set point D s to a depth/roll control algorithm 94, which computes a wing position set point w.
• the position controller may also be operated in a manual wing position configuration. In the manual state, the communication interface sends a signal M commanding the position controller to set its wings at preselected angles. The wing position set point w is ignored.
• the wing position set point w is selected for processing in a wing control algorithm 96.
• the actual wing position W is compensated to account for the roll of the position controller in a roll compensation algorithm 98, which produces an instantaneous roll-compensated wing position W r .
• An error signal e equal to w-W r is input to the wing control algorithm, which produces control signals that are sent to the wing actuators through a motor interface control 100.
• the control system can continuously control the actuators to change the sweep angles of either or both wings to cause the position controller to seek the desired depth or lateral position or bank angle.
• the response of the entire towed system is determined by its transfer function G(s).
• the wing position sensor determines the actual wing position W, and the roll sensor determines the actual roll, from which the roll-compensated wing position W r is determined.
• the depth sensor is mounted in the array, and the roll sensor and the wing position sensor are mounted in the position controller. But the depth sensor could alternatively be housed in the position controller's fuselage.
• FIGS. 14 and 15 Another version of a position controller is shown in FIGS. 14 and 15.
• the position controller 102 differs from the device in FIG. 1 most conspicuously in that it further includes a retractable stabilizing weight 104, shown in a fully extended position in FIG. 14.
• the stabilizing weight which is at the end of an arm, is pivoted into and out of a recess 106 between stowed and deployed states by a motorized actuator (not shown for drawing clarity). When deployed, the weight produces a righting moment, which reduces the load on the control system by providing passive stability.
• a wing receptacle 108 is formed in the fuselage 110 with a rearward segment 112 tilted off the longitudinal axis to accommodate the stabilizing weight's recess.
• the dihedral 112 of the wings 114, 115 is greater than for the wings of FIG. 1.
• the stabilizing weight helps stabilize the position controller in roll.
• FIG. 16 Another version of a position control device, shown in FIG. 16, has planar wings 116, 117, without camber or dihedral, extending from a fuselage 118. Openings 120 in the outer surface of the fuselage are linear, rather than segmented, and are disposed, for example, forming an angle 122 of about 7° with the longitudinal axis 27 of the position controller.
• the retractable stabilizing weight may be used in any of the versions shown as long as provisions are made to stow the stabilizing weight and wings simultaneously.
• the wing actuators may be realized in a variety of ways other than the linear lead screw mechanisms shown.
• a servo- or stepper-motor-driven pinion driving a star gear radially attached to the wing root can serve as the rotary actuator for each wing.

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Physics & Mathematics (AREA)
• Geology (AREA)
• Engineering & Computer Science (AREA)
• Acoustics & Sound (AREA)
• Environmental & Geological Engineering (AREA)
• Oceanography (AREA)
• Remote Sensing (AREA)
• General Life Sciences & Earth Sciences (AREA)
• General Physics & Mathematics (AREA)
• Geophysics (AREA)
• Laying Of Electric Cables Or Lines Outside (AREA)
• Other Liquid Machine Or Engine Such As Wave Power Use (AREA)
• Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)
• Placing Or Removing Of Piles Or Sheet Piles, Or Accessories Thereof (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (2)

Family

ID=39766693

Family Applications (1)

Country Status (6)

Cited By (9)

Families Citing this family (47)

Family Cites Families (27)

• 2007
  • 2007-02-13 US US11/674,539 patent/US7793606B2/en active Active
• 2008
  • 2008-02-08 EP EP08799653A patent/EP2118688A2/en not_active Withdrawn
  • 2008-02-08 JP JP2009549269A patent/JP2010517862A/ja not_active Ceased
  • 2008-02-08 WO PCT/US2008/053468 patent/WO2008115630A2/en not_active Ceased
  • 2008-02-08 AU AU2008229223A patent/AU2008229223B2/en not_active Ceased
  • 2008-02-08 CA CA2676934A patent/CA2676934C/en active Active

Also Published As

Similar Documents

Legal Events