Towed body

Abstract

The invention relates to a towed body (20) for towing behind a water vehicle, comprising a first pair of depressors (24) and a second pair of depressors (26). Each of the depressors (24, 26) has a variable inclination angle in order to allow a depth control of the towed body (20). Each of the depressors of the first pair (24) and the second pair (26) of depressors is designed to be actuated such that the inclination angle thereof is set independently of the inclination angle of one of the other depressors.

Description

[0001] Towed body

[0002] Description

[0003] The invention relates to a towing body for towing behind a watercraft, in particular a military watercraft.

[0004] The use of towed tow bodies for sonar antennas, especially for military sonar antennas, is well known. Typically, towed tow bodies are used for sonar antennas operated by surface vessels. The tow body can then be positioned in the water between the surface vessel and the towed tow antenna (single tow) or operated independently, without a connected tow antenna (dual tow / stand-alone operation).

[0005] The towed body has its own buoyancy / downforce. By means of the buoyancy or downforce of the towed body, the towing depth of the towed antenna can be adjusted depending on the towing speed and the length of the traction device between the surface vehicle and the towed body by knowing the buoyancy or downforce of the towed body, depending on the towing speed and the length of the traction device between the surface vehicle and the towed body. The towed body can have depressors (also known as vanes) to adjust its own buoyancy. These are usually fixed, however, so that the buoyancy or the passive running depth is set once during manufacture of the towed body. The towing depth can then only be changed by changing the length of the traction device or changing the travel speed of the surface vehicle. The travel speed, however, is, among other things,due to maneuvers, cannot be varied at will, so that in practice often only the change in the length of the towing device remains. The deployed cable length and thus the effective mass in the water depends on the speed with which the winch of the surface vehicle can retrieve the towing device and deploy it in a controlled manner. However, this speed is limited due to ship construction constraints (forces, energy, etc.). The system is therefore very sluggish in terms of its towing depth. Some towed bodies have two dependently movable depressors (also known as rudders) with which a variable towing depth of the towed antenna can be generated in certain depth ranges. However, these depressors cannot be controlled independently of one another, but are rather controlled synchronously in order to keep the tethered towed antenna (single tow) or the towed body alone (dual tow / stand-alone) at a predetermined depth.

[0006] The object of the present invention is therefore to create an improved concept for towed bodies and, if applicable, sonar towed antennas attached thereto.

[0007] This problem is solved by the subject matter of the independent patent claims. Further advantageous embodiments are the subject matter of the dependent patent claims.

[0008] Embodiments show a towed body for towing behind a watercraft, in particular a surface vessel, for example a ship. This means that the towed body can be connected to the watercraft by means of a traction device and pulled through the water by the latter. A towed antenna can in turn be attached to the towed body. Typically, the towed antenna has waterborne sound transducers for receiving waterborne sound, in particular waterborne sound receivers. Towed antennas are therefore suitable for passive sonar. Waterborne sound transducers for transmitting waterborne sound, in particular waterborne sound transmitters, can be arranged in the towed body. This makes it possible to form an active sonar system with the waterborne sound transducers of the towed body and the towed antenna. Furthermore, it is possible, in addition to or alternatively to the towed antenna, to position other sensors or, if appropriate, effectors over the towed body in a depth-variable manner.A traction cable, a traction rope or a traction belt can be used as a traction device.

[0009] The towed body has a first pair of depressors and a second pair of depressors, wherein the depressors each have variable inclination angles to enable depth control of the towed body. Depressors with variable inclination angles are also referred to as rudders. The depressors of the first pair and the second pair of depressors are each designed to be controlled such that their inclination angles are set independently of the inclination angle of one of the other depressors. This means that each depressor can be controlled independently. The control can be carried out by a signal processing unit which is arranged, for example, in the towed body or the watercraft. Due to the ability to control the depressors individually and independently of the other depressors, the depressors can fulfill the function of both an aileron and a depth rudder.Preferably, the depressors of the first pair of depressors form an angle of 180°. More preferably, the depressors of the second pair of depressors form an angle of 180°. This means that the depressors of the first pair of depressors and the second pair of depressors each lie in a common plane. It is also possible for the depressors of the first pair of depressors and the depressors of the second pair of depressors to lie in a common plane. In particular, one depressor of the first pair of depressors and one depressor of the second pair of depressors each point in the same direction from the towed body.

[0010] The idea is to make the towed body more agile by using several independently controllable, variable depressors. This means that increased, active depth variability is possible. This has several advantages. Firstly, the towed body can be actively stabilized in the water around both the roll and pitch axes using four independently controllable depressors. This allows the towed antenna, or rather the towed body itself, to move evenly in the water and have better reception and transmission characteristics. For example, this can be used to optimize the use of the towed antenna for a synthetic aperture sonar (SAS). However, for conventional use as an active or passive sonar, a smooth movement of the towed antenna in the water is advantageous. For example, this also reduces turbulence on the towed antenna, which can negatively affect the signal-to-noise ratio.Furthermore, it is possible to achieve greater diving depths of the towed body and thus of the towed antenna even at high speeds and with a short towing device. Both the high speed and the short towing device otherwise lead to the towed body experiencing greater buoyancy. However, using the four depressors, the diving depth can be increased even with a short towing device. The footprint of the towing device, i.e. the maximum required volume and thus weight for storing the towing device on board the watercraft, can thus be reduced, as the towing device can be dimensioned shorter to carry out the same missions. The variable depressors also enable the trimming (of the buoyancy / downforce) of the towed body depending on changed masses within the towed body, for example through replaceable elements such as sensors, or changes, e.g., in the mass, buoyancy, drag, etc. of the towed elements, e.g.by exchanging them.

[0011] In addition, towed antennas are designed for a specific speed range. This range can be extended by using the towed body, as the towed antenna can remain stable in the water, especially at low speeds.

[0012] A pair of depressors is understood to mean, in particular, two depressors arranged symmetrically with respect to an axially extending plane. This means that the plane extends from the tip (bow) to the end (stern) of the towed body. Advantageously, under ideal conditions, a normal to the plane runs parallel to the seabed or water surface.

[0013] A further advantage is that the four depressors can generate a very rapid change in buoyancy / downforce. This enables, among other things, the implementation of effective collision avoidance. The towed body also enables the use of towed antennas in shallow waters or near coastal areas, where towed antennas are currently not used for safety reasons. Furthermore, towed antennas are designed for a specified speed range. This range can be extended by using the towed body, as the towed antenna can remain stable in the water, especially at low speeds.

[0014] In addition, active control of the lift / downforce and the roll & pitch angle enables an expansion of the possible ship maneuvers when the towed body is deployed.

[0015] In exemplary embodiments, the two depressors of the first pair of depressors are arranged in a front half, in particular in a front third, of the towed body. Additionally or alternatively, the two depressors of the second pair of depressors are arranged in a rear half, in particular a rear third, of the towed body. The depressors in the rear part of the towed body can be arranged on a tail unit of the towed body. Thus, the leverage of the variable depressors is optimized, allowing the lift (or downforce) and the horizontal attitude, e.g., via the tail unit, to be optimized.

[0016] Advantageously, the towed body also features a rudder. This additional rudder, in combination with the four variable depressors, allows the towed body to be stabilized in all spatial axes.

[0017] Preferred embodiments of the present invention are explained below with reference to the accompanying drawings. It shows:

[0018] Fig. 1 : a schematic perspective view of a towed body with two pairs of variable depressors.

[0019] Before exemplary embodiments of the present invention are explained in more detail below with reference to the drawings, it is pointed out that identical, functionally equivalent or equivalent elements, objects and / or structures are provided with the same reference numerals in the different figures, so that the description of these elements shown in different exemplary embodiments is interchangeable or can be applied to one another. Fig. 1 shows a towed body 20 for towing behind a watercraft. The connection to the watercraft (not shown) can be made by means of a traction means 22. The towed body 20 has a first pair of depressors 24 and a second pair of depressors 26. In the view, one of the two depressors is visible at a time, the other depressor is arranged mirror-symmetrically on a casing 28 of the towed body 20.Plane 29, which is shown in detail, can serve as the plane of symmetry. The depressors 24, 26 each have variable inclination angles to enable depth control of the towed body 20. The mobility is indicated by the movement arrows 30a, 30b. Optionally, the depressors can be moved as a whole or they can have flaps to move part of the depressors.

[0020] Optionally, the towed body 20 has a (tail) fin 32. A rudder 34 can be arranged in the fin 32. A movement arrow 30c indicates the direction of movement of the rudder 34. Optionally, the depressors 26 of the second pair of depressors can also be arranged on the fin 32.

[0021] Furthermore, a towed antenna 36 can be attached to the towed body, in particular to its rear.

[0022] Further optionally, the towed body 20 has at least a plurality of waterborne sound transducers 38a, 38b or other "payloads," such as sensors. Points 38c indicate that the towed body 20 can have any number of waterborne sound transducers 38. The waterborne sound transducers can be arranged inside the hull or outside the hull, for example, in a belly 40.

[0023] The disclosed (water) sound transducers are designed for use underwater, particularly in the sea. The sound transducers can convert water sound into an electrical signal (e.g., voltage or current) corresponding to the sound pressure, the water sound signal. Furthermore, it is possible for the sound transducers to convert an applied electrical voltage into water sound. The sound transducers can therefore be used as water sound receivers and / or as water sound transmitters. The sound transducers can have a piezoelectric material, such as a piezoceramic, as the sensor material. The sound transducers can be used for (active and / or passive) sonar (sound navigation and ranging, dl: sound navigation and ranging). Hydrophones, for example, can be used as water sound transducers. The sound transducers are preferably not suitable for medical applications and are not used for medical applications.

[0024] Although some aspects have been described in connection with a device, it is understood that these aspects also represent a description of the corresponding method, so that a block or component of a device can also be understood as a corresponding method step or as a feature of a method step. Similarly, aspects described in connection with or as a method step also represent a description of a corresponding block, detail, or feature of a corresponding device.

[0025] The above-described embodiments are merely illustrative of the principles of the present invention. It is understood that modifications and variations of the arrangements and details described herein will be apparent to others skilled in the art. Therefore, it is intended that the invention be limited only by the scope of the following claims and not by the specific details presented in the description and explanation of the embodiments herein.

[0026] List of reference symbols:

[0027] 20 towed bodies

[0028] 22 traction means 24 first pair of depressors

[0029] 26 second pair of depressors

[0030] 28 Cover

[0031] 29 plane of symmetry

[0032] 30 movement arrows 32 fin

[0033] 34 rudder

[0034] 36 towed antenna

[0035] 38 waterborne sound transducers

[0036] 40 Belly

Claims

Patent claims 1 . Towing body (20) for towing behind a watercraft having the following features: - a first pair of depressors (24) and a second pair of depressors (26), the depressors (24, 26) each having variable angles of inclination to enable depth control of the towed body (20); - wherein the depressors of the first pair (24) and the second pair (26) of depressors are each designed to be controlled such that their inclination angles are adjusted independently of the inclination angle of one of the other depressors.

2. Towed body (20) according to claim 1, wherein the signal processing unit is designed to control the depressors of the first pair of depressors and the second pair of depressors independently.

3. Towed body (20) according to one of the preceding claims, wherein the two depressors of the first pair of depressors (24) are arranged symmetrically to an axially extending plane (29).

4. Towed body (20) according to one of the preceding claims, wherein the two depressors of the second pair of depressors (26) are arranged symmetrically to an axially extending plane (29).

5. Towed body (20) according to one of the preceding claims, wherein the two depressors of the first pair of depressors (24) are arranged in a front half, in particular front third, of the towed body (20).

6. Towed body (20) according to one of the preceding claims, wherein the two depressors of the second pair of depressors (26) are arranged in a rear half, in particular rear third, of the towed body (20).

7. Towed body (20) according to one of the preceding claims, wherein the towed body has a rudder (34).

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