Abstract:
An appliance for lowering and tracking an underwater vessel includes a carrier arranged on an end of a holding cable; a holding device on the carrier used to receive/release the underwater vessel with a controllable holding element; and a tracking device arranged on the carrier and used for acoustically determining the position of the underwater vessel lowered into the water. As a result, a light, compact lowering appliance is provided that is suitable for handling vessels on small platforms and ensures acoustically undisturbed operation of the tracking device, which is arranged on one end of the carrier, the carrier being mounted such that it can be pivoted on the holding cable in an articulated manner in a central longitudinal region thereof. Following release of the underwater vessel from the holding element, a pivoting device pivots the carrier including the tracking device out of a lowering position, into a tracking position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the National Stage filing under 35 U.S.C. §371 of International Application PCT/EP2006/009371, filed Sep. 27, 2006, and claims priority of German Patent Application 10 2005 058 475.6, filed Dec. 7, 2005, the subject matter of which, in their entireties, is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The invention relates to an appliance for deployment and tracking of an unmanned underwater vehicle as claimed in the precharacterizing clause of claim  1 . 
     Unmanned underwater vehicles are used, for example, for mine destruction, are remotely controlled from an airborne or waterborne platform, such as a helicopter or surface vessel, and are deployed into the water from the platform. A deployment appliance is used for this purpose and has a carrier which holds the underwater vehicle in a holder and is attached to a holding cable. The holding cable is unwound from the platform. The deployment appliance is advantageously equipped with a tracking apparatus which allows the unmanned underwater vehicle that has been deployed into the water and is a distance from the deployment appliance to be tracked, that is to say allows its position to be determined continuously. The tracking apparatus operates on the SSBL or USBL principle and has a plurality of hydrophones, which are arranged at a distance from one another, for receiving the sound pulses which are transmitted by a responder arranged on the underwater vehicle. The bearing angle to the underwater vehicle is calculated from the time-shifted reception of the sound pulses and from the phase shift that results from this between the electrical hydrophone output signals, and the distance to the underwater vehicle is calculated from the delay time of the sound pulses between the responder and the tracking device. 
     In a system for detection and destruction of underwater mines (EP 0 535 044 B1), the unmanned underwater vehicle which is equipped with an explosive charge is remotely controlled from a submerged platform, and the position of the underwater vehicle is determined continuously using a tracking apparatus, which is arranged on the platform and operates in the manner described above. The platform has a deployment appliance for deploying the underwater vehicle into the water. 
     It has already been proposed for an underwater platform such as this with a tracking device to itself be in the form of a deployment appliance for an unmanned underwater vehicle. The underwater platform is attached to a deployment cable and, for example, is lowered into the water from a helicopter. The holding apparatus for the unmanned underwater vehicle is arranged on the underneath of the platform, and the platform is equipped with its own electric-motor propulsion system. Once the platform has been deployed and has been released from the deployment cable, the platform is stabilized about its roll, pitch and yaw axes by means of vertically and horizontally acting maneuvering drive systems. The three-dimensional stabilization of the tracking device that this results in allows the position of the underwater vehicle to be found accurately even in poor sea-weather conditions, greatly reducing the risk of loss of tracking, that is to say of the acoustic link between the underwater vehicle and the tracking device breaking down. A three-dimensionally stabilized deployment appliance such as this has a relatively large volume, is heavy and is highly complex to manufacture. 
     The invention is based on the object of providing a lightweight, physically small deployment appliance with a tracking apparatus for an unmanned underwater vehicle, which is also suitable for handling on small platforms and ensures that the tracking apparatus operates acoustically without interference. 
     SUMMARY OF THE INVENTION 
     According to the invention, the object is achieved by the features of claim  1 . 
     The appliance according to the invention for deployment and tracking of an unmanned underwater vehicle has the advantage that the pivoting of the carrier after the underwater vehicle has been released results in the tracking apparatus being located at the deepest point of the carrier, with the acoustic performance of the tracking apparatus, in particular the acoustic link to the underwater vehicle, not being interfered with, or being interfered with only to a minor extent, by components on the carrier, such as the holder for the underwater vehicle. The elongated carrier, which is deployed vertically into the water, with the tracking apparatus arranged at its lower end means that the tracking apparatus is held in a sufficiently stable manner in the water, thus ensuring reliable position measurement of the underwater vehicle. An attitude sensor which, for example, is in the form of a compass stabilized on three axes, in the tracking apparatus provides information about the alignment of the hydrophone arrangement of the tracking device, and this is then included in the evaluation of the phase shift of the electrical hydrophone output signals. 
     Expedient embodiments of the deployment appliance according to the invention as well as advantageous developments and refinements of the invention will become evident from the further claims. 
     According to one preferred embodiment of the invention, the tracking apparatus is arranged at that end of the carrier which faces that part of the holding apparatus which grips the stern of the unmanned underwater vehicle. This has the advantage that the tracking apparatus cannot be damaged when the underwater vehicle is being unlatched from the holding apparatus, as a result of the front part of the holding apparatus, which grips the bow of the underwater vehicle, pivoting away. 
     According to one advantageous embodiment of the invention, the pivoting apparatus has a spring, which can be loaded by moving the carrier, preferably manually, to its deployment position. In this deployment position, the carrier is locked to the holding cable by means of a detachable locking apparatus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described in more detail in the following text with reference to one exemplary embodiment, which is illustrated in the drawing. 
         FIG. 1  shows a side view of a deployment appliance, in its deployment position, with an unmanned underwater vehicle accommodated in a holding apparatus, 
         FIG. 2  shows the same illustration as that in  FIG. 1  after the underwater vehicle has been unlatched from the holding apparatus and at the moment when the underwater vehicle enters the water, 
         FIG. 3  shows the same illustration as that in  FIG. 1 , with the underwater vehicle deployed in the water and the deployment appliance in the tracking position, and 
         FIG. 4  shows a schematic, enlarged illustration of the detail IV in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a perspective side view of the appliance  11  for deployment and tracking of a physically small, unmanned underwater vehicle  10 , having an elongated, narrow carrier  12  in the form of a plate, on whose underneath a holding apparatus  13  is arranged for the underwater vehicle  10  to be latched into. On its top, the carrier  12  has, approximately centrally, two attachment flanges  14  which are opposite one another and spaced apart, and between which an attachment lug  15  is positioned. A rotating bolt  16  passes through the two attachment flanges  14  and the attachment lug  15 , and holds the carrier  12  on the attachment lug  15  such that it can pivot. The attachment lug  15  forms the appliance-side, free end of a holding cable  17 , by means of which the carrier  12  is deployed with the underwater vehicle  10  from a platform into the water. In general, the platform for this purpose has a cable winch, by means of which the holding cable  17  can be fed out and retrieved again. Signal and power supply lines run in the interior of the holding cable  17 . The platform may be airborne or waterborne, for example in the form of a helicopter or a surface vessel. In general, a damping element  18  is also arranged between the holding cable  17  and the attachment lug  15 , in order to largely reduce shocks affecting the deployment appliance  11  when the deployment process is stopped quickly. 
     The holding apparatus  13  has a rear holding element  131 , which is arranged fixed to the carrier  12 , and a front holding element  132 , which is arranged on the carrier  12  such that it can pivot. At least one hydraulic or compressed-air cylinder  19  is provided in order to pivot the front holding element  132 , and acts via at least one piston rod on the front holding element  132 , which is mounted on the carrier  12  such that it can pivot. 
     As can be seen in  FIG. 1 , the stern of the underwater vehicle  10  is latched into the rear holding element  131 , and its bow is latched into the front holding element  132 , by the front holding element  132  being pivoted downwards, and thus closing the holding apparatus  13 . In order to unlatch the underwater vehicle  10 , the front holding element  132  is pivoted slightly upwards by means of the hydraulic or compressed-air cylinder  19 , as a result of which the front holding element  132  releases the bow of the underwater vehicle  10 , and the latter falls out of the rear holding element  131  by virtue of its weight. This is illustrated in  FIG. 2 . 
     In the exemplary embodiment, the underwater vehicle  10  is connected to the deployment appliance  11  via a signal cable with a small cross section. A glass-fiber cable  24  is normally used as the signal cable and is unwound from two glass-fiber spools during movement of the underwater vehicle  10 . One glass-fiber spool is located in the stern of the underwater vehicle  10 , and the other glass-fiber spool is accommodated in a spool receptacle  21  arranged on the carrier  12 . The spool receptacle  21  is held in a cage  22  and is locked against falling out. As or immediately after the front holding element  132  of the holding apparatus  13  is pivoted upwards, the lock on the spool receptacle  21  in the cage  22  is also released, so that the spool receptacle  21  falls out of the cage and sinks into the water  40  until a connecting cable  23  between the spool receptacle  21  and the carrier  12  is stretched tight ( FIG. 3 ). As soon as the spool receptacle  21  has reached its final position in the water  40  and the electrical propulsion systems for the underwater vehicle  10  have been activated, the glass-fiber cable  24  is unwound from the spool receptacle  21 , and is at the same time unwound from the glass-fiber spool arranged in the stern of the underwater vehicle  10 , so that the glass-fiber cable  24  is not subjected to any tensile load, or only to a small tensile load. 
     At its rear free end, where the cage  22  is also arranged, the carrier  12  has a tracking apparatus  25  for tracking the underwater vehicle as it moves away. As is illustrated schematically in  FIG. 1 , the tracking apparatus  25  comprises a hydrophone arrangement  26  which projects beyond the free end of the carrier  12 , and an attitude sensor  27  which, for example, is a three-axis-stabilized compass. The hydrophone arrangement  26  comprises, in a known manner, a plurality of hydrophones at a distance from one another, and receives sound pulses transmitted from a responder  28  arranged on the underwater vehicle  10 . An evaluation unit  29  downstream from the hydrophone arrangement uses the phase shifts between the electrical hydrophone output signals and in taking account of the alignment of the hydrophone arrangement, which is measured by the attitude sensor  27 , to calculate a bearing angle to the underwater vehicle  10 . The sound pulses are initiated electrically in the responder  28  via the glass-fiber cable  24 , and the evaluation unit  29  measures the delay time of the sound pulses from the underwater vehicle  10  to the hydrophone arrangement  26 , and uses this to calculate the distance between the underwater vehicle  10  and the deployment appliance  12 . The position of the underwater vehicle  10  can be found at any time from the bearing angle and the distance. 
     A pivoting apparatus  30  for pivoting the carrier  12  from its deployment position, in which the underwater vehicle  10  can be unlatched from the holding apparatus  13 , to a tracking position, in which the tracking apparatus  25  is located at the maximum distance below the articulation point of the carrier  12  on the holding cable  17 , that is to say at the maximum distance below the rotating bolt  16 , is located between the carrier  12  and the holding cable  17 , to be more precise between the carrier  12  and the attachment lug  15  on the holding cable  17 . Since the carrier  12  is aligned approximately at right angles to the holding cable  17  when in its deployment position, the pivoting apparatus  30  rotates the carrier  12  through about 90°. The pivoting apparatus  30  is inactive in the deployment position of the carrier  12  with the holding apparatus  13  closed, and is activated on or after opening of the holding apparatus  13  and the unlatching of the underwater vehicle  10  associated with this. 
     The pivoting apparatus  30  has a spring  32  which is loaded in the deployment position of the carrier  12 , and a detachable locking apparatus  31  which, when the spring  32  is loaded, locks the carrier  12  in its deployment position on the holding cable  17 , to be more precise on the attachment flange  14  of the holding cable  17  ( FIG. 4 ). In the schematically illustrated exemplary embodiment, the spring  32  is a spiral spring  33  whose inner spring limb  331  is fixed to the attachment lug  15 , and whose outer spring limb  332  is fixed to the front attachment flange  14  of the carrier  12  in  FIG. 4 . The locking apparatus  31  has a spring-loaded blocking element  34  which is arranged such that it can move axially on the rear attachment flange  14  in  FIG. 4 , and a locking groove  35  which interacts with the blocking element  34  and is formed in the attachment lug  15 . 
     When the carrier  12  is in the deployment position as illustrated in  FIG. 4 , the front end of the blocking element  34  is pushed into the locking groove  35  by the locking spring  36 . The carrier  12  and the holding cable  17  are therefore firmly connected to one another. In the exemplary embodiment, the locking apparatus  31  can be released by means of an electromagnet  37 , which is lifted out of the locking groove  35  when current flows through the blocking element  34 , which forms the armature of the electromagnet  37 . The influence of the spiral spring  33  pivots the carrier  12 , from which the underwater vehicle  10  has been released, in the direction of the arrow  38  in  FIG. 4 . That end of the carrier  12  to which the tracking apparatus  25  is fitted, is pivoted downwards, and enters the water  40 , as is illustrated in  FIG. 3 . The attachment lug  15  has a second locking groove  39 , which is offset through an angle of 90° with respect to the locking groove  35 . During the pivoting movement of the carrier  12  relative to the attachment lug  15  on the holding cable  17 , with the electromagnet  37  unlocked, the spring-loaded blocking element  34  enters the second locking groove  39  and locks the carrier  12 , which is aligned approximately parallel to the holding cable  17 , in this position as illustrated in  FIG. 3 . 
     If the aim is to deploy an underwater vehicle  10  from a platform in a sea region, then the carrier  12  is first of all manually pivoted to a rotation position in which it is aligned approximately horizontally. During this pivoting movement of the carrier  12 , the spiral spring  33  is loaded, and the locking apparatus  31  becomes effective at the end of the pivoting movement, as a result of the blocking element  34  entering the locking groove  35  under the influence of the locking spring  36 . The underwater vehicle  10  is now inserted into the holding apparatus  13 , and the holding apparatus  13  is closed via pivoting the front holding element  132 . The spool receptacle  31  is inserted into the cage  20 , and is likewise locked in it. 
     The deployment appliance  11  with the underwater vehicle  10  latched in the holding apparatus  13  is now lowered to the water surface  41  from the platform by paying out the holding cable  17 . A release control unit  42  arranged on the carrier  12  activates the hydraulic or compressed-air cylinder  19 , which pivots the front holding element  132  upwards so that it is lifted off the bow of the underwater vehicle  10 . The released underwater vehicle  10  falls out of the rear holding element  131  and enters the water through the surface  41 , as is illustrated in  FIG. 2 . As the underwater vehicle  10  falls out, this also releases the spool receptacle  21 , which falls out of the cage  22  and likewise enters the water  40  through the water surface  41 , in order then to sink until the connecting cable  23  is stretched tight. Once the underwater vehicle  10  and the spool receptacle  21  have fallen out, current is passed through the release control unit  42  of the electromagnet  37 , as a result of which the blocking element  34  is pulled out of the locking groove  35 . The loaded spiral spring  33  rotates the carrier  12  in the direction of arrow  38  ( FIG. 4 ) until the spring-loaded blocking element  34  enters the second locking groove  39 . The tracking apparatus  35  is at the maximum distance below the rotating bolt  16  and enters the water  40  through the water surface  41 . The holding cable  17  is now paid out further until the entire deployment appliance is submerged below the water surface. The tracking apparatus  25  assumes an optimum attitude below the water surface  41  and can maintain an acoustic link, without interference, with the responder  28  in the underwater vehicle  10  during the movement of the underwater vehicle  10 .