Autonomous submersible vehicle and method for pulling in same

Abstract

A method for pulling an autonomous submersible vehicle into a mother ship. The method includes the steps of letting out a floating line from the mother ship, allowing at least part of a capturing line to rise from the submersible vehicle using a capturing buoy, to cause the submersible vehicle to cross under the floating line in such a way that the capturing line with the capturing buoy becomes caught on the floating line, and to draw the submersible vehicle to the mother ship by pulling in the floating line.

Claims

1. A method for pick-up of an autonomous submersible vehicle in a mother ship, comprising the steps: letting out a floating line from the mother ship, so that the floating line runs at a level of a water surface, allowing rise of at least part of a capturing line using a capturing buoy from the submersible vehicle, wherein a first end of the capturing line is attached to the submersible vehicle and a second end of the capturing line is attached to the capturing buoy so that the capturing buoy floats at a water surface, passing under the floating line with the submersible vehicle so that the capturing line with the capturing buoy is caught on the floating line, and pulling the submersible vehicle to the mother ship by picking up the floating line.

2. Method according to claim 1, wherein: the submersible vehicle passes under the floating line such that capturing buoy hooks onto the floating line using a catch device; and the catch device slides to the end of the floating line through the forward motion of the mother ship.

3. Method according to claim 1, wherein a driving course that is controlled by the submersible vehicle is compared with an actual driving course of the submersible vehicle and a deviation above a predetermined threshold, confirms successful hooking of the capturing buoy to the floating line.

4. Method according to claim 1, wherein: an end of the floating line that faces away from the mother ship is provided with a location buoy that is released along with the floating line, the location buoy has a location transmitter and the location transmitter transmits a location signal so that the submersible vehicle can locate the location buoy, and another location transmitter is provided at the stern of the mother ship at the floating line or is released otherwise into the water, and the submersible vehicle passes under the floating line between the location buoy and the another location transmitter.

5. Method according claim 1, wherein: the submersible vehicle allows rise of a part of the capturing line before passing under the floating line, so that the submersible vehicle passes under the floating line with a shortened capturing line and a remaining part of the capturing line can be drawn from a receiving cage of the submersible vehicle, after the capturing line with the capturing buoy has been caught on the floating line, wherein one end of the capturing line remains fixed on the submersible vehicle.

6. Method according to claim 1, wherein: the submersible vehicle is brought to the mother ship, and a lifting gear of a deck crane is guided along the capturing line or a support line to a lifting anchor of the submersible vehicle.

7. Autonomous submersible vehicle comprising: a capturing line with a capturing buoy; a release mechanism for releasing the capturing buoy and at least part of the capturing line; and a floating line configured to run at a level of a water surface such that if the submersible vehicle passes under the floating line, the capturing line with the capturing buoy is caught on the floating line.

8. Autonomous submersible vehicle according to claim 7, wherein: one end of the capturing line or a first end of a support rope is fixed on a submersible vehicle in a region of a lifting anchor; and a central portion of the capturing line is attached in a front area of the submersible vehicle, and/or a second end of a support line is attached to the central region of the capturing line.

9. Autonomous submersible vehicle according to claim 8, wherein: the capturing line is stored in a front cassette on the submersible vehicle and can rise at least partially from there.

10. Vehicle assembly comprising an autonomous submersible vehicle according to claim 7, and a mother ship for picking up the submersible vehicle, wherein the mother ship comprises a release and pick-up mechanism for discharging and recovering the floating line and a base station for picking up the submersible vehicle.

11. The method according to claim 3 wherein the predetermined threshold is above 30° C.

12. A method according to claim 2 wherein the catch device is a catch hook.

13. The autonomous submersible vehicle of claim 8 wherein one end of the capturing line or a first end of a support rope is fixed on the submersible vehicle in an upper, central region of the submersible vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is exemplified in more detail by way of embodiments with reference to the accompanying drawings.

(2) FIGS. 1 to 7 illustrate a method for picking up an autonomous watercraft, based on positions and/or behavior of the mother ship and/or the autonomous submersible vehicle.

(3) FIG. 8 illustrates a controlled, vibration-reduced lifting and getting an autonomous submersible vehicle on deck.

(4) FIG. 9 illustrates the guidance of a lifting gear to a lifting anchor of an autonomous submersible vehicle.

(5) FIG. 10 illustrates the guidance of a lifting gear to a lifting anchor of an autonomous submersible vehicle in another illustration.

(6) FIG. 11 shows an autonomous submersible vehicle in a state ready for pick-up.

DETAILED DESCRIPTION

(7) FIGS. 1 to 7 illustrate step-by-step the pick-up process and Attaching a submersible vehicle, to be picked up by a mother ship, including any proposed arrangements.

(8) FIG. 1 also shows a gently moving forward mother ship 2 that has let out a floating line 4 with location buoy 6 from behind. The floating buoy 6 is prepared for housing a wireless and GPS receiver in order to represent the position of the buoy 6. The buoy is equipped with a sonar transmitter and a signal or position light and it is connected to the floating line 4.

(9) The buoy 6 is thrown from the deck at the stern of the mother ship 2 into the water. An electric winch unwinds the floating line 2, namely to about 80 m, while the mother ship moves forward slowly at a speed of about 1 knot to support the unwinding process. Preferably, it is proposed to arrange another sonar transmitter outside the stern of the mother ship, in addition to the sonar transmitter of location buoy 6.

(10) Once the location buoy 6 is at a suitable distance to the mother ship, the autonomous submersible vehicle to be picked up will be prompted by an acoustic submersible modem to start the pick-up process.

(11) To this end, the submersible vehicle is commanded to a particular position from which it can securely pass under the floating line 4 between the mother ship and the 2 location buoy 6. A capturing buoy of the submersible vehicle is released on command and the submersible vehicle, which is submerged approximately to a depth of 5 m, draws the capturing buoy, which is provided with a downwardly pointing hook, from behind. This scenario is illustrated schematically in FIG. 2, in which the submersible vehicle 8 draws a capturing buoy 12 via a capturing line 10, wherein the capturing buoy 12 essentially floats on the water surface 14. The capturing buoy 12 is equipped with a hook 16, that substantially points down. FIG. 2 illustrates an autonomous submersible vehicle 8 also with a lifting anchor 18 having a catch hook for engagement.

(12) The speed V.sub.U of the autonomous submersible vehicle 8 is, for example, two knots. The total length of the capturing line 10 is, for example, about 25 m.

(13) Preferably, the process described above can be carried out automatically by automatically issuing a pick-up command to the autonomous submersible vehicle 8 via the acoustic link. The submersible vehicle 8 will automatically release the capturing buoy and pass under the floating line between the two sonar transmitters.

(14) A support line 20, which can be, for example 15 m long, connects the lifting anchor 18, in particular, the indicated hook, with the capturing line, e.g. after a length of 9 m. This support line 20 is stowed in a front cassette in the submersible vehicle 8. The capturing line 10 is initially not fully withdrawn by the capturing buoy 12, but is limited to a length whose value is slightly larger than the immersion depth of the autonomous submersible vehicle 8. This length to which the capturing line 10 is first drawn, can be limited, for example to 8 m. The remaining 17 m, to continue with the above example, is mechanically pulled out when the submersible vehicle 8 is drawn behind the mother ship.

(15) FIG. 3 illustrates passing of the submersible vessel 8 under the floating line 4 at the speed V.sub.U of the submersible vehicle 8.

(16) By passing under, the capturing buoy 12 is drawn against the floating line 4 such that the floating line 4 enters the catch hook 16.

(17) Due to the forward motion V of the mother ship 2, the floating line 4 will slide through the catch hook 16 until this hook on the location buoy 6 has reached the end of the floating line 4. This scenario is illustrated in FIG. 4.

(18) By the pulling force of the mother ship 2, the submersible vehicle is drawn with its bow towards the mother ship 2. This effect of drawing is detected by the navigation software of the submersible vehicle and the engines of the submersible vehicle are stopped. The detection occurs based on the fact that the specified or commanded direction is different from the actual direction by more than 30 degrees. This check is only active during a pick-up process, so as to avoid any malfunctions during an investigation trip, exploratory trip or the like of the submersible vehicle.

(19) The floating line 4 is then picked up by the winch until both buoys, namely location buoy 6 and capturing buoy 12, are on deck of the mother ship 2. The support line 20 is then attached to the base station as long as the pulling force from the mother ship 2 still acts on the submersible vehicle 8 via the floating line 4 and the capturing line 10. The winch 22 that is only shown schematically on some of the figures will again let out the floating line a bit, namely to the extent that the pulling force is no longer transmitted via the floating line 4 and the capturing line 10, but the support line 20. The speed of the mother ship 2 here is very low or even zero. Both buoys, namely the location buoy 6 and the capturing buoy 12, can then be removed safely and the floating line 4 and the capturing line 10 are connected. This procedure prevents any accidents that could be caused by a pulling force in the lines.

(20) The winch 22 then continues to rewind while excavation or lifting gear, such as a lifting line, is installed on a crane hook, in particular, a conventional crane hook of a deck crane. FIG. 5 shows the scenario in which the support line 2 is attached to a base station on the mother ship and thus, to the mother ship. If the submersible vehicle 8 was brought close to the mother ship 2 used by rewinding of the winch 22, a crane hook is arranged above the submersible vehicle 8. The lifting gear or the excavating gear that can be designed as a lifting line that is placed in a loop can be guided along the support line 20 to the hook of the lifting anchor 18.

(21) If the deck crane is only located on the side of the mother ship 2 and can pick up the submersible vehicle 8 only there, the mother ship 2 should make a turn, which is indicated in FIG. 6.

(22) FIG. 9 illustrates the guidance of the lifting line 24, which is the lifting gear or excavating gear here, along the support line 20 to the lifting hook 26 of lifting anchor 18 of the submersible vehicle 8. The lifting hook 26 also has a locking mechanism 28, which prevents the lifting line 24 from slipping out of the lifting hook 26 as soon as it has reached its position there. The submersible vehicle 8 can then be raised above the crane hook 30 by a crane.

(23) In comparison with FIG. 9, FIG. 10 shows an overview and partly schematically illustrates how a lifting line 24 can be guided to a lifting anchor 18. To this end, the submersible vehicle 8 is attached to its bow 34 with the capturing line 10 at a mooring line 36. The mooring line 36 is located on the mother ship, so as to allow the submersible vehicle 8 being drawn at this capturing line 10 behind the mother ship, if the mother ship moves ahead at least with a low drive. Instead of the mooring line 36, using a winch same as the winch 22 in FIGS. 1-8 is proposed, wherein the submersible vehicle is attached via the capturing line 10. A crane 26, which is also attached to the mother ship, has the lifting line 24, wherein the specific attachment of the lifting line 24 onto the crane 26 is not shown because the crane 26 is shown here only symbolically. The support line 20 is attached to the lifting anchor 18 and is also guided to the mother ship. The lifting line 24 is placed in a loop around this support line 20 and thus, can be guided along this to the submersible vehicle 8, namely to the lifting anchor 18.

(24) FIG. 7 shows a position of the lateral pick-up of the submersible vehicle 8 by a crane 32 onto the mother ship. 2 Referring to FIG. 7, which also applies to the other figures, in particular, FIGS. 1-8, it should be noted that the illustrations provide an overview and in particular, the scale need not reflect reality. In particular, the submersible vehicle 8 is usually significantly smaller than the mother ship 2.

(25) FIG. 7 shows that the submersible vehicle 8 is brought very close to the mother ship 2 by means of the winch 22 and the capturing line 10. The submersible vehicle 8 can now be lifted by the crane 32, wherein the support line 20 can be used as auxiliary means.

(26) To avoid or at least reduce swaying of the submersible vehicle 8 while hanging on the crane 32, the winch 22 continues to exert a pulling force on the submersible vehicle 8 via the capturing line 10; this is indicated in FIG. 8. Preferably, the winch 22 can be turned on a corresponding rotary support, such as a turntable, towards the bow of the submersible vehicle 8. This is done basically passively or automatically by the applied pulling forces between the winch 22 and the submersible vehicle 8.

(27) Preferably, the autonomous submersible vehicle is equipped with a capturing buoy with hook and capturing line that is attached to the nose of the autonomous submersible vehicle. Further, a trigger or release mechanism is provided in order to release the capturing buoy, and thus, also release a corresponding part of the capturing line fixed to the capturing buoy. The submersible vehicle has a bow hook that allows the submersible vehicle to navigate through the water at a speed of three knots. Preferably, two cassettes are provided to take up the lines. Furthermore, a load hook is provided in the central region of the autonomous submersible vehicle to lift it. This is, in particular, part of a lifting anchor of the submersible vehicle.

(28) Preferably, an acoustic modem is provided, including adaptation to command or direct the submerged autonomous submersible vehicle via an acoustic modem. Preferably, the submersible vehicle is intended for implementation of an automatic retrieval and an automatic pick-up, if this relates to actions of the submersible vehicle.

(29) FIG. 11 shows an submersible vehicle 8, with a bow 34, stern 38, bottom side 40 and upper side 42. A capturing line 10 is arranged at the bow 34 of the submersible vehicle 8 and leads to a capturing buoy 12 that floats on the water surface 14. The capturing buoy 12 also has a catch hook 16, which faces forward, as the submersible vehicle 8 moves forward at a low speed V.sub.U while pulling the capturing buoy 12 in that direction.

(30) On the upper side 42 of the submersible vehicle 8 and in the vicinity of a lifting anchor 18, a support line 20 that is mounted in a central region of the capturing line 10 is fixed. An attachment point in this central region bears the reference number 44 and is only schematically indicated in the FIG. 11. In particular, the length ratios between the length of the submersible vehicle 8, the lengths of the capturing line 10 and support line 20 and the actual position of the attachment point 44 are not representative of the actual scale.