DE102016221597A1 - Autonomous underwater vehicle and stacking device - Google Patents

Abstract

An autonomous underwater vehicle has a fuselage having an angular cross-sectional shape with an aspect ratio of at most 1: 1.5. According to a further aspect, an autonomous underwater vehicle for deep sea use has a hull with a material content of greater than 50% of a polymer material which has a specific gravity of less than 1.0.

Description

Embodiments of the present invention relate to an autonomous underwater vehicle with special geometry and to a stacking device for stacking the autonomous underwater vehicles. Further embodiments relate to an underwater vehicle with specific material characteristics.

Autonomous underwater vehicles (AUVs) are used in such a way that they independently carry out missions, such as mapping, in underwater operation, in particular in deep-sea operation. In the prior art AUVs distinction is made between those with a pressure chamber or those with a pressure-neutral or partially pressure-neutral design; in this context, for example, to the US 5,995,882 directed. Autonomous submersibles, in contrast to manned submersibles, have a very significant cost advantage, allowing for much more cost-effective underwater exploration. In this respect, it is a common goal to advance the technology of underwater vehicles so that the use of underwater vehicles is more cost-effective.

AUVs often have an outer shell / frame made of steel, aluminum or titanium with additional buoyancy bodies (eg foam). Since syntactic foam is a spec. Weight of 0.5 to 0.8, you need a lot of buoyancy material to compensate in the water the output of the metal body. Materials for buoyant bodies are for example in the US 4,021,589 , of the US 6,153,294 or the EP 0883648 A1 disclosed.

Today's advanced autonomous diving robot technology requires motherships that cost up to $ 60,000 per day and require a capital investment of several $ 1 million apiece, which limits their use to very few industries and applications. Existing technologies can not operate as large-scale as would be required to explore the ocean floor (deep-sea: more than 1000 to 11000 m depth) of all oceans unless they make significant compromises in the resolution, power and weight of sensors. Therefore, there is a need for an improved approach.

Object of the present invention is to provide an autonomous underwater vehicle that has advantages in terms of cost in terms of production and use.

The object is solved by the independent claims.

Exemplary embodiments of the present invention provide an autonomous underwater vehicle with a fuselage which, at least in the cross-sectional area, has an angular shape with an aspect ratio of at most 1: 1.5 or 1: 125. For example, the condition applies to a polygonal shape such as e.g. a triangular, square, hexagonal shape or a rhombic shape, too.

Embodiments of the present invention is based on the finding that, starting from an angular hull shape with a small aspect ratio, the stackability of the AUVs can be substantially improved, so that substantially more AUVs can be carried along with the same sized mother ship. For example, in a conventional 40-foot ISO container, the launch and recovery system, including 12 submersibles, can be stacked when they are nested side by side / on top of each other starting from the new shape.

It has also been recognized that this angular shape does not present major drawbacks to flow resistance, especially at the low speeds of AUVs. According to further embodiments, the autonomous underwater vehicle or its hull is lightweight, e.g. of a polymeric material having a specific gravity less than 1.0, e.g. Polypropylene or unfilled polypropylene or a polyethylene / polypropylene blend. It may according to further embodiments, the AUV have a pressureless (pressure neutral) structure, i. So be executed without external pressure armor.

According to further embodiments, the angular shape is realized in that the hull has at least two flat, but preferably at least three flat side surfaces. These are angled in accordance with embodiments, e.g. arranged at an acute angle or at a 90 ° angle. For example, if the hull has four side surfaces, the arrangement of the side surfaces to each other at 90 ° angle is advantageous, since so a square or rectangular cross section is created. This square or rectangular cross section can be stacked very well. According to preferred embodiments, the side surfaces, e.g. the rectangularly arranged side surfaces, in a rest position relative to the ground or the water surface arranged such that two side surfaces to the water surface include a 45 ° angle. This means that the side surfaces do not run parallel to the ground or to the water surface in the rest position.

According to further embodiments, the hull forms in the arrangement discussed above (not parallel to the water surface arranged side surfaces and acute angle between the two or more planar or rectilinear side surfaces) of a so-called keel, which according to preferred embodiments has an acute angle, such as a 60 ° angle. According to embodiments, antennas for the sonar (an interferometric sonar, a synthetic aperture sonar and / or a sidescan sonar) may be provided in this keel. This angle is very advantageous especially with regard to the radiation.

According to a further embodiment, an autonomous underwater vehicle is provided with a fuselage (without shape restriction) having a material content of greater than 50% (or even 90%, 99% or 100%) of a polymer material having a specific gravity less than 1.0. According to embodiments, the polymer material used is a polyolefin, such as polypropylene or, in particular, low-filled or unfilled polypropylene.

The central idea of this aspect is that the o.g. Polymer material / polypropylene serves both as a structural and as a buoyant material due to their material properties. These materials are inexpensive, easy to form and have excellent buoyancy properties due to their specific gravity less than 1 and 0.91 respectively. These low specific weights are achieved in particular with pure (unfilled) polymer materials. The breaking strength of a component made of polypropylene can be further increased by adding polyethylene, without significantly increasing the density.

Further embodiments provide a stacking device for stacking at least two autonomous underwater vehicles. This stacking device can be part of a container (ISO container) or integrated in a container. The stacking device has the peculiarity of stacking the AUVs optimally so that the two AUVs are juxtaposed, such that one side surface of one AUV is parallel with the other side surface of the other AUV (ie, slightly spaced or directly engaged ).

• 1a eine schematische Darstellung eines AUVs gemäß einem Basisausführungsbeispiel;
• 1b eine Stapelvorrichtung für das AUV gemäß Ausführungsbeispielen aus 1a;
• 2 eine schematische Darstellung eines AUVs gemäß einem erweiterten Ausführungsbeispiel;
• 3a eine Bergevorrichtung für das AUV gemäß einem Ausführungsbeispiel; und
• 3b-d eine weitere Bergevorrichtung für das AUV gemäß einem weiteren Ausführungsbeispiel.

Further developments are defined in the subclaims. Embodiments of the present invention will be explained below with reference to the figures. It shows:

• 1a a schematic representation of an AUV according to a basic embodiment;
• 1b a stacking device for the AUV according to embodiments 1a ;
• 2 a schematic representation of an AUVs according to an extended embodiment;
• 3a a recovery device for the AUV according to an embodiment; and
• 3b-d another recovery device for the AUV according to another embodiment.

Before explaining embodiments of the present invention with reference to the accompanying drawings, it should be noted that like-acting elements and structures are provided with the same reference numerals, so that the description of which is mutually applicable or interchangeable.

1a shows an AUV 10 with a hull 12 , This one is considering the cross section of the hull 12 viewed, square or diamond-shaped. This forms a hull 12 with four flat surfaces 12a-d out, with the area 12a arranged at an angle α to the surface b angled and the surface 12b by an angle β with respect to the surface 12c etc., so that the four angles (α, β, γ, δ) adjust.

For example, in this embodiment, the angles β and δ may be acute angles, i. For example, angles at 60 °, and the angles α and γ obtuse angles, and then around 120 °. Alternatively, of course, all angles α to δ be the same and thus be 90 ° or chosen to be any other way.

In addition, the hull has a small aspect ratio of not more than 1: 1.5 or 1: 1.25 in relation to the cross section in order to enable good stackability. The aspect ratio describes the relationship between the maximum and the minimum transverse extent. In the case of the illustrated diamond, therefore, the ratio of the two diagonals to one another.

It should also be noted at this point that optionally the side surfaces 12a-d all are arranged so that these at least in the resting position of the AUV 10 not parallel to the ground or to the water surface. In other words, this means that the surfaces are arranged at an angle. Here, for example, in rest position, ie at normal Vorrausfahrt, the areas 12a and 12d towards the ground or the waterline an angle ε in the range of 45 °, here 60 °, occupy.

It should be noted at this point that a flat surface can also be understood to mean a slightly curved or curved surface.

Due to the angular shape, the AUVs 10 very good space-saving stacking, such as based on 1b is shown. It is assumed that each vehicle has a maximum length of 2.20 m, so the AUV 10 across a standard ISO container ( 40 Inch with internal dimension 2,352 m) can be accommodated. With these dimensions, not only a space-saving stacking, but also a good accessibility is guaranteed.

1b shows how a variety of AUVs 10 with rectangular cross section by means of a stacking device 20 are stacked. The stacking device 20 know here a honeycomb structure 20 on. Through this stacking device 20 With the above mentioned dimensions, about 12 vehicles can be accommodated together with a carrier system (for deployment and recovery) in a single 40ft ISO container. The arrangement of the 12 submersible vehicles takes place transversely in the standard containers, so that even accessories, such as the rescue tool, can be accommodated in the same. Thus, it is possible with a single ISO container to carry all the equipment for a medium-sized mission, so it is not absolutely necessary to go out with large and expensive mother ships at sea. According to embodiments, the AUVs may be stacked in individual transport boxes in the container. In this context, it should be noted that 12 submersibles from an interferometric sonar with typical 117 kHz in 14 hours allow a mapping of 500 km ² .

Also in relation to the AUV 10 itself has this rectangular or generally angular arrangement advantages. In such a geometry, the batteries can be arranged well, since no "dead" spaces form through the curves. Lithium-ion batteries have proven themselves not only for the power supply of autonomous diving robots. The battery management, the drive, the operation of the sensors and lighting and the control computer must be as energy efficient as possible. Only in this way can it be guaranteed that a mission duration of 16 to 24 hours can be achieved with relatively little weight and volume of the batteries. Moreover, it is also noted that hydrodynamic vision is not detrimental to this hull shape, as the flow resistance is not unduly detrimental.

If you now according to other embodiments, the fuselage 12 of the AUV 10 lightweight construction material, such as polypropylene, a copolymer of polypropylene (eg, together with (poly) ethylene having an ethylene content of, for example, <5.0 wt.% or <1.0 wt.%) or another incompressible polymer also has a big weight advantage per AUV. In the case of polypropylene, in the present case, for example, a so-called unfilled / pure polypropylene is assumed, since this has the required buoyancy properties (specific weight). Unfilled polypropylene is understood as meaning a pure polypropylene which, in contrast to industrial polypropylene, does not require fillers such as natural calcium carbonate (GCC), synthetic calcium carbonate (PCC) or carbon black (soot). While unfilled polypropylene is more expensive than filled polypropylene, it is much cheaper than syntactic foam and also much easier to process. Due to the low weight of the drive can be made small, which in total contributes to a very battery-saving operation.

Examples of suitable polymer materials according to embodiments are polyolefins (belonging to the group of thermoplastics), such as polypropylene (PP) or, in particular, low-filled (<1%, 5%, 10% or 15% filler fraction) or unfilled polypropylene. Unfilled polypropylene has a specific gravity in the range of 0.91. These materials of the group polyolefins are inexpensive, easy to form and have due to their / Archimedes weight less than 1 excellent buoyancy properties, so that the material itself acts as a buoyant body.

Depending on the depth of the water, syntactic foams with a spec. Weight of 0.4 kg / l, when e.g. the high compressive strength is not needed. The background to this is that usually very pressure-resistant foams are the more expensive the lighter they are.

As an alternative to polypropylene, as mentioned above, a copolymer of polypropylene and polyethylene may also be used. Polyethylene is chemically very similar to polypropylene and, as a copolymer, has the advantage that it does not become brittle at 0 ° C and thus offers better mechanical properties over a broad range.

These materials also have the further advantage that they are incompressible or, to be exact, have a high compression modulus. Here, the compression modulus (in the range of 10 ¹¹ Pa) is sufficiently high, so that it can be used as a structural element in deep-sea operation (at least 300 m, preferably greater than 1,000 m or even in the range of 10,000 m).

With regard to the variant with (unfilled) polypropylene as the hull material, it should be noted that due to the specific weight of the PP, a frame / hull made of PP can be designed many centimeters thick, since it is nevertheless lighter in water than with metal frame and foam.

According to embodiments, a pressure-neutral structure (internal pressure = pressure) is used in conjunction with the supporting outer structure, for example, from the above-described unfilled polypropylene, so that syntactic foam can be omitted in whole or in part. The low payloads allow further advantages, namely that a variety of control mechanisms can be effectively integrated in addition to the conventional control over rudders (which are flowed through the vehicle movement):

Thus, a control in the sense of maneuvering, for example by sliding trim, e.g. over weights (in the keel), which are movable by means of toothed belts, or by pumping ballast tanks, realized. By pumping ballast water or pumping and pumping ballast water, the lowering and emergence of the AUV can be easily realized. As an alternative to the trim control, a front-mounted side thruster would also be conceivable (without an element projecting beyond the outer shape), which, starting from the small mass, may also be dimensioned very small.

According to further embodiments, the reference is to 1a chosen variant with the acute angles, in particular the acute 60 ° angle in the keel an advantageous; This applies, for example, when a sonar is to be mounted in the keel. The antennas in the 60 ° angle can radiate very well, which optimizes the use of sonars, such as interferometric sonar, synthetic aperture sonars or sidescansonare.

2 shows another AUV 10 ' that a hull 12 ' having a square cross-section, wherein the nose 12n has a rounded shape and the stern 12h forms a conical spout, in which then the propeller 12p is arranged. The propeller 12p For example, it can be single or double-pitched. At the stern 12h are also the oars 12r intended.

As explained above, the AUV serves 10 ' for example, for mapping and therefore has an antenna for a sonar in this embodiment. This is in the keel 12k , which separately to the main body 12 ' is scheduled provided. The keel 12k has an acute angle (ideally 60 °) in cross section.

According to embodiments, a camera and an LED lighting may be mounted on each submersible to additionally be able to take photos. LED and camera are away from each other, so that images are better (lighting from the side). This arrangement has already been successfully developed and tested in the deep sea at our partner GEOMAR Helmholtz Center for Ocean Research in Kiel. It will be supplemented with allogites for the automated optimization of underwater images through intelligent electronics. The photography is realized in cooperation with the GEOMAR Helmholtz Center for Ocean Research in Kiel, who have already developed and tested corresponding solutions.

According to further embodiments, it is advantageous for the mapping when a position determination is made directly. The position determination is ensured, for example, via a built-in inertial navigation system that is supported by USBL and "inverted" LBL by GPS signals. Both USBL and inverted LBL are underwater navigation systems based on times of water sound between the object and multiple reference points. They are used to determine the position of objects or devices underwater.

According to embodiments, the electronics, such as e.g. the sonar electronics, BMS, the control computer, INS, etc. in a separate pressure body, which is provided inside the fuselage be provided.

According to further embodiments, in addition to the above-described electronic units, other electronic units may also be incorporated into the autonomous vessel, such as e.g. a depth sensor (pressure sensor) to be integrated.

According to further embodiments, a recovery device in the form of a small parent vehicle is provided. Examples of this are in 3a - 3d shown.

3a shows the recovery device 50 , which is here as so-called SWATH (Small Waterplane Area Twin Hull) is executed. Here are two hulls 52a and 52b provided, between which a gap 50z arises, by means of which the AUV can be recorded. In the gap 50z According to further embodiments, a carrier, here two oblique plates, arranged such that a maximum large surface contact to AUV (eg 30% of the total AUV surface) is formed, so that this (if it is made of structurally weaker lightweight materials) is not damaged , Here are the recording means 54 realized by two oblique plates parallel to the angled outer surfaces of the trunk of the AUV.

The flat described elements, like the two hulls 52a and 52b and therefore also the gap 50z as well as the receiving means 54 are lowered in Bergen according to further embodiments below the water surface. For this purpose, then points the recovery device 50 float 56a-c on. The fact that a lowering takes place is the recovery device, ie the SWATH 50 as well as the AUV to be recovered stable in the water as the displacement center of gravity lies below the water surface. Consequently, there is also little "material" in the wave zone, so that even heavy waves can not matter. Further, a long residence of the AUV or a continuous transport through the wave zone is avoided by the recovery device 50 During the recovery, the AUV is shielded from the wave fronts (eg by more than 50% of the waterline being surrounded). According to embodiments, the lowering and recovery can be done by pumping and pumping of ballast water.

According to embodiments, the SWATH 50 dismantled or has at least one retractable element, so that the SWATH 50 can be stowed in containers together with the AUVs.

According to preferred embodiments, it would also be conceivable that the number of SWATHs 50 are equal to or equal to the number of AUVs in the container.

At this point it should be noted that the AUV 10 or 10 ' not only can have a polygonal cross-section, but also a pointed nose and / or tail. As a result, the so-called penguin shape or spindle shape arises.

3b shows another recovery device 50 ' with also two hulls 52a ' and 52b ' , At each of the two hulls 52a ' and 52b ' may according to embodiments an outboard as drive 53 ' be provided. The two hulls 52a ' and 52b ' are by means of curved elements 55 ' interconnected, so that in turn a gap 50z ' is created. At these elements 55 ' are the receiving means 54 ' , here a kind of net provided.

When Bergen AUV drives into or under the gap 50z ' after the net 54 ' was lowered below the water surface. By lifting the net 54 ' then the actual Bergen takes place.

In 3c (three-dimensional view) and 3d (Side view) is another variant of a SWATH 50 " shown. This includes two hulls 52a " and 52b " that have a connection construction 55 " connected to each other. The connection construction 55 " has a float 55s " mounted so that under the same 55s "a gap area 50z " is formed. This area 50z " becomes laterally through the connection construction 55 " and down through the hulls 52a " and 52b " as well as the receiving means 54 " limited. This area 50z " is open on bow or stern (here bow), so that the AUV can retract.

When Bergen becomes the lower area 52a " . 52b " and 54 " of SWATH 50 " Lowered below the water surface, leaving the AUV in the gap 50z " can retract, taking while lifting the lower area 52a " . 52b " and 54 " of SWATH 50 " the AUV is recorded.

The SWATH 50 " can optionally have two integrated drives 53 " (one for each hull 52a " / 52b " ) exhibit.

The embodiments described above are merely illustrative of the principles of the present invention. It will be understood that modifications and variations of the arrangements and details described herein will be apparent to others of ordinary skill in the art. Therefore, it is intended that the invention be limited only by the scope of the appended claims and not by the specific details presented in the description and explanation of the embodiments herein.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 5995882 [0002]
• US 4021589 [0003]
• US 6153294 [0003]
• EP 0883648 A1 [0003]

Claims (18)

Autonomous underwater vehicle (10, 10 ') with the following features: a hull (12, 12 ') having an angular shape with a maximum aspect ratio of 1: 1.5 in relation to a cross section. Autonomous underwater vehicle (10, 10 ') according to Claim 1 wherein the hull (12, 12 ') has at least two flat surfaces (12a, 12b, 12c, 12d). Autonomous underwater vehicle (10, 10 ') according to Claim 1 or 2 , wherein the hull (12, 12 ') is rotationally symmetric by less than 180 °, 90 ° or 60 °. Autonomous underwater vehicle (10, 10 ') according to one of the preceding claims, wherein the aspect ratio is a maximum of 1: 1.25. Autonomous underwater vehicle (10, 10 ') according to one of the preceding claims, wherein the hull has at least two mutually angled (α, β, γ, δ) surfaces (12a, 12b, 12c, 12d). Autonomous underwater vehicle (10, 10 ') according to Claim 5 wherein the angles (α, β, γ, δ) are acute angles (α, β, γ, δ) or are perpendicular angles (α, β, y, δ). Autonomous underwater vehicle (10, 10 ') according to one of Claims 2 to 6 , Wherein none of the two surfaces (12a, 12b, 12c, 12d) in rest position in the water runs parallel to the water surface. Autonomous underwater vehicle (10, 10 ') according to one of the preceding claims, wherein the hull (12, 12') has a material content of more than 50% of a polymer material having a specific gravity less than 1.0, or a material content of more than 50 % of a polyolefin or a polypropylene or a copolymer of polypropylene. Autonomous underwater vehicle (10, 10 ') according to one of the preceding claims, wherein the polymer material, the polyolefins or the polypropylene is unfilled or has a filler content of less than 10%. Autonomous underwater vehicle (10, 10 ') according to one of the preceding claims, wherein the hull (12, 12') is pressure-neutral. Autonomous underwater vehicle (10, 10 ') according to one of the preceding claims, wherein the hull (12, 12') has a keel (12k) in which an antenna for a sonar, an interferometric sonar, a synthetic aperture sonar and / or a sidescan sonar having. Autonomous underwater vehicle (10, 10 ') according to Claim 11 wherein the keel (12k) has an acute angle (α, β, γ, δ) and / or wherein the keel (12k) has a 60 ° angle (α, β, y, δ). An autonomous underwater vehicle (10, 10 ') according to any one of the preceding claims, wherein the autonomous underwater vehicle (10, 10') comprises a control mechanism; wherein the control mechanism has a variable loading weight with respect to its position relative to the center of gravity of the underwater vehicle (10, 10 '). Stacking device (20) for at least two stored autonomous underwater vehicles (10, 10 ') according to one of Claims 2 to 13 in that the at least two autonomous underwater vehicles (10, 10 ') are mounted in the container such that one of the at least two surfaces (12a, 12b, 12c, 12d) of the one autonomous underwater vehicle (10, 10') is adjacent and parallel to one another the surfaces (12a, 12b, 12c, 12d) of the other autonomous underwater vehicle (10, 10 ') is arranged. Stacking device (20) according to Claim 14 wherein the at least two autonomous underwater vehicles (10, 10 ') are each stored in a box in the container and the boxes are stackable such that one of the at least two surfaces (12a, 12b, 12c, 12d) of the one autonomous underwater vehicle (10 , 10 ') is arranged adjacent and parallel to one of the surfaces (12a, 12b, 12c, 12d) of the other autonomous underwater vehicle (10, 10'). Autonomous underwater vehicle (10, 10 '), having the following features: a hull (12, 12 ') with a material content of greater than 50% of a polymer material having a specific gravity of less than 1.0, wherein the autonomous underwater vehicle (10, 10 ') is designed for deep-sea use. Autonomous underwater vehicle (10, 10 ') according to Claim 16 wherein the polymeric material is a polyolefin or polypropylene or copolymer of polypropylene. Autonomous underwater vehicle (10, 10 ') according to Claim 16 or 17 , wherein the polymer material is unfilled or has a filler content less than 10%.

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