EP2440449B1 - Method for detecting anomalies on a submarine object - Google Patents

Description

The invention relates to a method for detecting anomalies on an underwater object, in particular on the underwater part of a hull of a moored watercraft, according to the preamble of claim 1.

In times of increasing terrorist threat from civilian and military installations, their permanent protection becomes increasingly important. In particular, underwater objects, such as foundations of conveyors and wind farms, docks, hulls of in-port vessels and submarines, are exposed to underwater manipulation by divers or guided underwater vehicles unprotected. So unnoticed, for example, can be attached to detention mines, which are then remotely ignited.

The document US 2004/0083940 discloses the features of the preamble of claim 1 and is considered to be the closest prior art.

Out DE 10 2005 014 555 A1 For example, a mine-hunting system and a mine-hunting method with a plurality of autonomously-acting submersibles are known wherein a first group of such underwater vehicles having sensors is used for mine-finding, and a second group of such under-water vehicles is used to control located mines.

Out US 2009/0090286 A1 is an armed, remotely operated vehicle with video and sonar sensors known.

Next are out DE 10 2005 062 109 A1 a method and a device for the defense against underwater invading persons are known, wherein first a

Person is detected and tracked and subsequently an unmanned underwater vehicle is used to ward off the detected person.

Furthermore, it is off DE 43 02 455 A1 an underwater drone for controlling mines, said underwater drone having a suitable metal detection antenna device.

Finally is off DD 300 802 A7 an underwater body with a fixed arrangement of hydroacoustic transducers for basic distance measurement known that can be used universally in three modes.

The invention has for its object to provide a cost-effective method for detecting or detecting anomalies of underwater objects, z. B. from there illegally mounted foreign bodies, such as custody, smuggled goods and the like. To specify that is efficient and largely automated without underwater use of people can be performed.

The object is achieved by the features in claim 1.

The inventive method has the advantage that with a simple sensor equipment, such as acoustic sensor for Querabstandsmessung and pressure cell for depth determination, a very reliable scanning of the underwater object can be performed and by navigating the underwater small vehicle with a constant transverse distance to the underwater object, a profile of the underwater object is obtained in whose profile line an anomaly present on the underwater object, eg an adhering foreign body, clearly emerges. This is due to the fact that when detecting the anomaly by the acoustic sensor, the undersea small vehicle continues due to its inertia characterized by constant transverse distance to the underwater object ride, however, in the measurement profile of the transverse distance measuring acoustic sensor but a profile change, such as a burglary or Depression in the profile line appears, which has subsided again, if the cruise control of the underwater small vehicle by the navigation device would respond to the changed transverse distance, so that the underwater small vehicle regardless of the short-term changing transverse distance to the underwater object continues its course in the predetermined, constant transverse distance to the underwater object unchanged. The detection of the anomaly in the measurement profile line of the acoustic distance sensor can be brought directly to the Wamanzeige in a monitoring center, for example via a towed by the underwater small vehicle light guide and trigger a diving operation for inspection and / or removal of the anomaly, without the underwater small vehicle its Inspection must interrupt or cancel. This provides a significant time savings between detecting and eliminating the anomaly.

Advantageous embodiments of the method according to the invention with advantageous developments and embodiments of the invention will become apparent from the other claims.

According to an advantageous embodiment of the method, the position of the underwater small vehicle relative to the underwater object is determined at least when detecting an anomaly. By determining the position of the underwater small vehicle an object-related localization of the anomaly can be easily made and the inspection and / or disposal operation by divers time-compressed and efficient.

According to an advantageous embodiment of the invention, the underwater small vehicle drives at a constant speed and the driving time is continuously measured while driving. If an anomaly is detected, the position of the anomaly is determined from the previously measured travel time and the speed of the underwater small vehicle as well as the depth of the underwater small vehicle. The time measurement is started when the predetermined transverse distance of the underwater small vehicle to the underwater object is measured for the first time. By this procedure, the position of the underwater small vehicle and thus the object-related position of the anomaly can be determined by a simple time measurement.

According to an advantageous embodiment of the invention, a repeated traversing of the underwater object is carried out and changed at each shutdown, the constant depth. By this movement of the underwater object in different depths can be determined sufficiently accurately with a simple acoustic sensor with small vertical bundling of the acoustic scanning beam and the depth component of the anomaly for the diving operation. In this case, the depth of travel change of the underwater small vehicle can be performed directly at the end of the underwater object by a 180 ° turn of the small vehicle or after a complete avoidance of the underwater object.

Fig. 1

eine Seitenansicht eines in einem Hafenbecken vertäuten Oberflächenschiffes,

Fig. 2

eine Draufsicht des Oberflächenschiffes in Fig. 1,

Fig. 3

ein bei Abtasten des Rumpfes des Oberflächenschiffes in Fig. 1 und 2 durch einen akustischen Abstandssensor bei Fahrt des Unterwasser-Kleinfahrzeugs entstehendes Diagramm des Querabstands des Unterwasser-Kleinfahrzeugs vom Rumpf des Oberflächenschiffes in Abhängigkeit von der Fahrzeit,

Fig. 4

ein Blockschaltbild einer Vorrichtung zur Durchführung des Verfahrens zum Aufspüren oder Erkennen einer Anomalie am Rumpf des Oberflächenschiffes in Fig. 1 und 2.

The inventive method is described in more detail below with reference to an embodiment shown in the drawing. In a schematic representation:

Fig. 1

a side view of a moored in a harbor surface ship,

Fig. 2

a top view of the surface ship in Fig. 1 .

Fig. 3

one upon scanning the hull of the surface ship in Fig. 1 and 2 Diagram showing the transverse distance of the underwater small vehicle from the hull of the surface ship as a function of the travel time, as a result of an acoustic distance sensor when the underwater small vehicle is traveling;

Fig. 4

a block diagram of an apparatus for performing the method for detecting or detecting anomaly on the hull of the surface ship in Fig. 1 and 2 ,

In order to explain the method presented here for detecting, detecting or detecting anomalies on a stationary underwater object, is in Fig. 1 and 2 a surface ship 11 shown schematically, which is located in a harbor basin 12 and moored to a pier 13, that is moored with lines 14, is.

In the underwater area, an anomaly 16 is shown on the hull 15 of the surface ship 11, e.g. an adhesive mine or a container filled with contraband can be.

In order to detect such anomaly 16 on the otherwise smooth hull 15 of the surface ship 11, an unmanned underwater small vehicle 17 is used. Such unmanned, self-propelled underwater small vehicles are widely known in different assembly with sensors and measuring device. The underwater small vehicle 17 used here has, for example, four propeller drives 18 which are used to control or navigate the underwater small vehicle 17 by a navigation device 19 (FIG. Fig. 4 ) are controlled separately. Depending on the speed of the individual propeller drives 18, of which two are arranged vertically one above the other and two horizontally next to each other, the underwater small vehicle 17 can go straight or be steered to the right or left and up or down. At least one acoustic distance sensor 20 for measuring a horizontal distance extending horizontally to the vehicle axis and a depth sensor 21 for determining the diving depth of the underwater small vehicle 17 are present as sensors in the underwater small vehicle 17 used here. Such an acoustic distance sensor 20 may be, for example, a simple echosounder which emits sound pulses and receives the echoes produced by reflection of the sound pulses and measures the time between the transmission and the echo reception. Taking into account the speed of sound, the distance is calculated from the measured time up to the object which triggers the reflection of the sound pulses. The depth sensor 21 is for example a simple pressure box. The output signals of the sensors 20, 21 are supplied to the navigation device 19.

The underwater vehicle small vehicle 17 is used by the surface ship 11 or from the pier 13 into the water, for example - as in Fig. 1 and 2 dargstellt is - behind the stern of the surface ship 11, and travels along the fuselage 15 of the surface ship 11. While driving the underwater small vehicle 17 by means of the acoustic distance sensor 20 continuously the horizontal transverse distance of the underwater small vehicle 17 from the fuselage 15 is measured. The underwater small vehicle 17 is thereby from the navigation device 19 controlled so that it adheres to a predetermined transverse distance from the fuselage 15 at a constant depth. For this purpose, the navigation device 19 (FIG. Fig. 4 ) on the one hand the depth of travel and the transverse distance as setpoint values T _set and d _set set and on the other hand, the measured values of distance sensor 20 and depth sensor 21 as actual values d and T supplied. Depending on this, a corresponding control loop in the navigation device 19 generates control commands for the four propeller drives 18, which hold the underwater small vehicle 17 on the addressed course.

The measured during the ride of the underwater small vehicle 17 continuously from the distance sensor 20 actual lateral distance d is also continuously compared with the predetermined target transverse distance d _Soll and then when the actual transverse distance d significantly below the target transverse distance d _target drops to presence detected an anomaly. The underwater small vehicle 17 is preferably connected via a connecting line 22 (FIG. Fig. 1 ) is connected to a mission monitoring center aboard the surface ship 11, and if an abnormality is detected, an alarm can be triggered via the connection line 22. At the moment of the Anomalieaufspürung also the current position of the underwater small vehicle 17 is determined relative to the fuselage 15 of the surface ship 11 and communicated via the connecting line 22 of the mission monitoring center. The position determination is carried out in a simple manner in that the underwater small vehicle 17 at constant speed, which is the navigation device 19 as speed _setpoint v set is set, runs and from a starting point from the travel time t is measured. The travel time t _A measured at the time of detecting the anomaly 16 gives the traveled distance s _A in the predetermined diving depth T _Soll , whereby the position P _A (s _A ; T _A ) of the underwater small vehicle 17 is fixed. If the time t _{o is} selected as the starting point of the time measurement, at which the distance sensor 20 first measures a transverse distance d after exposure of the underwater small vehicle 17, which corresponds to the predetermined desired transverse distance d _Soll , then the output position P _A (s _A ; T _A ) of the underwater small vehicle at the same time the position of the anomaly 16 on the fuselage 15 of the surface ship 11th

In Fig. 4 By way of example, a block diagram of a device installed in the underwater small vehicle 17 is shown, with which the presented method for detecting or detecting the anomaly 16 is performed. In addition to the already mentioned navigation device 19 and the previously mentioned sensors 20, 21, the device also has a first edge detector 23, a timer or timer 24, a comparator 25, a second edge detector 26, a gate circuit 27 and a multiplier 28. The output of the acoustic distance sensor 20 is connected both to the navigation device 19 and to the inputs of the edge detectors 23, 26 and the comparator 25. The comparator 25 is supplied via a second input of the predetermined transverse distance d _{Soll of} the underwater small vehicle 17 from the fuselage 15 of the surface ship 11. The gate circuit 27 can be controlled via the output of the comparator 25 and connects the output of the timer 24 and the input of the multiplier 28, as the multiplier, the target speed V _{Soll of} the underwater small vehicle 17 is supplied. The outputs of the two edge detectors 23, 26 are connected to the navigation device 19.

Fig. 3 shows to illustrate the presented method, a diagram in which during the ride of the underwater small vehicle 17 is measured by the acoustic distance sensor 20 transverse distance d is shown as a function of travel time t. The underwater small vehicle 17, which is exposed behind the stern of the surface vessel 11, picks up speed and arrives at the tt depth T _setpoint at the t ₀ at a constant speed. During this route, the acoustic distance sensor 20 measures against the pier wall and thus the Transverse distance d to the pier wall, which is significantly greater than the navigation device 19 predetermined setpoint d _target . If the underwater small vehicle 17 reaches the fuselage 15 of the underwater hull 11, a clear measured value jump occurs at the exit of the acoustic distance sensor 20, since the transverse distance d measured now by the distance sensor 20 against the fuselage 15 is much smaller than that previously measured against the pier wall transverse distance. This negative measurement jump leads at the output of the first edge detector 23 to a control pulse, with the one hand, the distance control circuit of the navigation device 19 is turned on and on the other hand, the timer 24 is started. The underwater small vehicle 17 is now controlled on a course on which the underwater small vehicle 17, the predetermined transverse distance d _target to the fuselage 15 maintains constant.

At time t _A , the underwater small vehicle 17 reaches the anomaly 16 on the fuselage 15, and the output signal of the acoustic distance sensor 20 briefly drops below the desired value d _setpoint . At the output of the comparator 25, which constantly compares the output from the distance sensor 20 actual value of the transverse distance d from the fuselage 15 with the predetermined target value of the transverse distance d _desired , a pulse occurs, which causes the gate 27 for short-term closing. As a result, the travel time t _A currently measured by the timer 24 is given to the multiplier 28. In the multiplier 28, the currently determined travel time t _A is multiplied by the predetermined target speed v _{Soll of} the underwater small vehicle 17. The resulting route s _A together with the predetermined depth T _{set of} the underwater small vehicle 17 determines the position of the underwater small vehicle 17 at the moment of finding the anomaly 16 can be transmitted via the connecting line 22 to the mission monitoring center on board the surface ship 11 and integrated into an alarm display. Based on the alarm display, a scuba diving mission can be started by the monitoring center to inspect and eliminate the anomaly 16, wherein the position of the submarine small vehicle 17 determined by the reported route s _A and the reported diving depth T _Soll indicates the position P _{A of} the anomaly 16 the target for divers use.

Independently of this, the underwater small vehicle 17 continues its journey with a constant transverse distance d _Soll from the hull 15 of the surface ship 11. If the underwater small vehicle 17 has reached the end of the fuselage 15 and drives beyond it, the acoustic distance sensor 20 again measures the transverse distance to the pier wall, which is significantly greater than the transverse distance to the fuselage 15. At the output of the distance sensor 20, a clear measured value jump occurs towards higher readings. The positive edge of the measured value jump is detected in the second edge detector 26. The latter generates a control pulse, which reaches the navigation device 19 and there a maneuver of the underwater small vehicle 17 triggers, such as a turning maneuver to a changed depth.

The described process of running the hull 15 through the underwater small vehicle 17 is repeatedly performed with different depth of the underwater small vehicle 17, so that the entire body 15 is completely scanned in the vertical dimension of the acoustic distance sensor 20. It makes sense for the underwater small vehicle, after leaving the hull area, to make a 180 ° turn and, in the next depth, drive the hull 15 in the opposite direction to its previous lane. In this case, the underwater small vehicle 17 must be equipped with a second acoustic distance sensor whose measuring direction is rotated by 180 ° with respect to the first acoustic distance sensor 20.

All mentioned in the above description of the figures, in the claims and in the introduction of the description features can be used individually as well as in any combination with each other.

Claims (4)

1. A method for locating anomalies (16) on an underwater object, in particular in the underwater area of a hull (15) of a moored water vehicle, characterized in that an unmanned miniature underwater vehicle (17) that is equipped with a navigation device (19) and an acoustic sensor that measures transversely to the direction of travel moves at a constant depth (T_soll) along the underwater object during which the transverse distance of the miniature underwater vehicle (7) from the underwater object is measured with the acoustic sensor, that the miniature underwater vehicle (17) is steered with the navigation device (19) in such a manner that the miniature underwater vehicle (17) maintains a constant given transverse distance (d_soll) from the hull (17), and that the measured transverse distance (d) is continuously compared with the given transverse distance (d_soll) and upon a significant deviation an anomaly (16) on the underwater object is recognized.
2. The method according to claim 1, characterized in that the underwater object is passed by several times and upon each pass the constant depth (T_soll) of the miniature underwater vehicle (17) is changed.
3. The method according to claim 1 or 2, characterized in that the position of the miniature underwater vehicle (17) to the underwater object is determined at least upon recognition of an anomaly.
4. The method according to claim 3, characterized in that the miniature underwater vehicle (17) travels with a constant speed (v_soll), that the travel time (t) is continuously measured and that upon recognition of an anomaly the horizontal component of the position of the anomaly (16) is determined from the travel time (t_A) measured up to that point and from the travel speed (v_soll) of the miniature underwater vehicle (17).

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