Unmanned Underwater Vehicle and Method for Localizing and Examining An Object Arranged At The Bottom Of A Body Of Water and System Having the Unmanned Underwater Vehicle

Abstract

The invention relates to an unmanned underwater vehicle for localizing and examining an object, for example a pipeline, arranged at the bottom of a body of water. For this purpose, the underwater vehicle has object localization means and object examination means. The underwater vehicle has a sonar device with 3D underground sonar for collecting measurement data. The object localization means are designed for three-dimensional acoustic localization of local sections of the object which are arranged both above and below the surface of the bottom of the body of water by means of these measurement data while the underwater vehicle is simultaneously moving away over these local sections for the purpose of examining local sections of the object by means of the object examination means. As a result, the invention allows a pipeline to be simultaneously surveyed and inspected as it is traversed once. The invention also relates to a system having the underwater vehicle and also to a method for localizing and examining the object.

1 - 15 . (canceled) 
     
     
         16 . An unmanned autonomous underwater vehicle for localizing and examining an object arranged at a bottom of a body of water, such as a pipeline or a marine cable, said vehicle comprising:
 an object localization means for localizing the object;   an object examination means for examining the object, and   a sonar device having a 3D underground sonar for collecting measurement data,
 wherein, utilizing the measurement data, the sonar device and the object localization means are designed for three-dimensional acoustic localization of local sections of the object that are arranged both above and below the surface of the bottom of the body of water while the underwater vehicle is simultaneously moving along the local sections, thereby examining at least one of the local sections and adjacent local sections of the object utilizing the object examination means. 
   
     
     
         17 . The vehicle according to  claim 16 , further comprising:
 an object path identification means for identifying the local object path of the object by means of the localized local sections irrespective of whether the local sections are at least one of resting on the surface of the bottom of the body of water, are buried under the bottom of the body of water, and are partially exposed within the bottom of the body of water; and   an object path tracking means for adapting a trajectory of the underwater vehicle utilizing the identified local object path such that a lateral offset of the trajectory relative to the identified local object path is kept at least one of below a specific threshold value and substantially constant when a deviation from the lateral offset is below the specific threshold value.   
     
     
         18 . The vehicle according to  claim 17  further comprising a multi-sensor system that in combination with the 3D underground sonar is structured and operable to collect the measurement data and at least one of localize the object and examine the object, the multi-sensor system comprising at least one of:
 at least one camera, 
 a side scan sonar device, 
 a multibeam sonar device, 
 a front scan sonar device, and 
 at least one magnetic sensor of a magnetic field detection device. 
 
     
     
         19 . The vehicle according to  claim 18 , wherein the multi-sensor system is further structured and operable to:
 collect measurement data that are suitable for surveying a local surface of the bottom of the body of water below the underwater vehicle,   identify the position of the detected local sections of the object relative to the local surface of the bottom of the body of water, and   classify, utilizing the identified position, whether the local sections are sections of the object that at least one of rest on the surface of the bottom of the body of water, are buried under the bottom of the body of water, are partially exposed within the bottom of the body of water, and are underwashed within the bottom of the body of water.   
     
     
         20 . The vehicle according to  claim 19  further comprising a navigation means for providing navigation data for independent navigation of the underwater vehicle to determine the respective position of the respectively localized section of the object and for assigning at least one of the navigation data and the measurement data to the respective position, the navigation means comprising at least one of:
 a pitch sensor for determining the rotational movement of the underwater vehicle about its transverse axis; 
 a roll sensor for determining the rotational movement of the underwater vehicle about its longitudinal axis; 
 a magnetic compass for determining the direction and orientation of the underwater vehicle relative to field lines of the earth's magnetic field; 
 an echo sounder for determining a water depth below the underwater vehicle; 
 an aneroid barometer for determining a water pressure at a depth of the underwater vehicle below the water surface, wherein the determined water pressure is used to determine the depth of the underwater vehicle below the water surface; 
 a device of an “ultra short baseline” underwater navigation system for determining the position using travel time measurements of underwater sound signals to a plurality of other devices in the water; 
 a waterborne sound speed sensor for determining a sound speed in the water; 
 a transponder device for transmitting signals in response to reception of signals; 
 a responder device for transmitting signals in response to the reception of signals; 
 an ultrasonic doppler profile flowmeter for determining a water flow relative to the underwater vehicle; 
 at least one acceleration sensor for determining an acceleration of the underwater vehicle in an inertial reference system; 
 a measuring probe for determining a salt content and a temperature of the surrounding water and for determining a depth of the measuring probe below the water surface; 
 a receiver device for receiving satellite signals of a satellite-assisted navigation system, and for determining the position of the underwater vehicle by means of the satellite signals; and 
 a turbidity sensor for determining a turbidity of the surrounding water. 
 
     
     
         21 . The vehicle according to  claim 20 , wherein the receiver device for receiving satellite signals of a satellite-assisted navigation system comprises a global positioning system (GPS). 
     
     
         22 . The vehicle according to  claim 20 , wherein the 3D underground sensor comprises a plurality of waterborne sound transducers arranged in series, as a physical aperture and an artificial aperture for spanning an observation surface permitting the three-dimensional localization of the object by means of repeatedly determined measurement data of the waterborne sound transducers, wherein the underwater vehicle has at least one sensor carrier that is pivotable relative to the longitudinal axis of the underwater vehicle, to which the waterborne sound transducers are fastened at least in their majority, in each case at a plurality of different intervals relative to a point of reference on the longitudinal axis, wherein the waterborne sound transducers that determine the measurement data are arranged symmetrically relative to the longitudinal axis of the underwater vehicle, such that a center of a scanning region that is able to be scanned by means of the measurement data has a lateral offset to the longitudinal axis of the underwater vehicle. 
     
     
         23 . The vehicle of  claim 22 , wherein the waterborne sound transducers are fastened to the at least one sensor carrier a plurality of different intervals relative to a point of reference on the pivot axis of the respective sensor carrier. 
     
     
         24 . The vehicle of  claim 22 , wherein the center of the scanning region that is able to be scanned by means of the measurement data has a lateral offset of at least one half of a metre to the longitudinal axis of the underwater vehicle. 
     
     
         25 . The vehicle according to  claim 22  further comprising a control device comprising:
 a means for manoeuvering the underwater vehicle to an operating depth defined by a submerged position; 
 a means for manoeuvring the underwater vehicle to the submerged position after reaching the operating depth; 
 a means for carrying out a search routine after reaching the submerged position, wherein available prior knowledge about the position of the object is taken into consideration by the search routine; 
 a means for calculating and traversing a start-up trajectory to a start position defined as a function of the determined position of the object; and 
 a means for following the trajectory located above a determined object path. 
 
     
     
         26 . A system comprising:
 an autonomous underwater vehicle comprising:
 an object localization means for localizing the object; 
 an object examination means for examining the object, and 
 a sonar device having a 3D underground sonar for collecting measurement data, 
 wherein, utilizing the measurement data, the sonar device and the object localization means are designed for three-dimensional acoustic localization of local sections of the object that are arranged both above and below the surface of the bottom of the body of water while the underwater vehicle is simultaneously moving along the local sections, thereby examining at least one of the local sections and adjacent local sections of the object utilizing the object examination means; 
   a mission planning device for producing control data for controlling the mission;   a control data transmission device for transmitting the control data from the mission planning device to the underwater vehicle;   a measurement data reading device for reading measurement data stored during the mission; and   a measurement data evaluation device for at least one of:
 classifying sections of the object as sections which at least one of rest on the surface of the bottom of the body of water, are buried under the bottom of the body of water, are partially exposed within the bottom of the body of water, and 
 determining a condition of the object. 
   
     
     
         27 . A method for localizing and examining an object arranged at the bottom of a body of water, by means of an unmanned underwater vehicle, that comprises an object localization means that localize the object and that has an object examination means that examine the object, said method comprising:
 collecting measurement data utilizing a sonar device with 3D underground sonar of the vehicle   localizing, utilizing the object localization means, local sections of the object by utilizing the measurement data in a three-dimensional acoustic manner, while the underwater vehicle is simultaneously moving along the local sections of the object and simultaneously the object examination means examines at least one of the local sections and adjacent local sections of the object, irrespective of whether the local sections are at least one of resting on the surface of the bottom of the body of water, are buried under the bottom of the body of water, and are partially exposed within the bottom of the body of water.   
     
     
         28 . The method according to  claim 27 , further comprising
 identifying, utilizing an object path identification means, the local object path of the object utilizing the localized sections irrespective of whether the local sections are at least one of resting on the surface of the bottom of the body of water, are buried under the bottom of the body of water, and are partially exposed within the bottom of the body of water; and   adapting the trajectory of the underwater vehicle, utilizing an object path tracking means, utilizing the identified object path such that a lateral offset of the trajectory relative to the identified local object path is kept at least one of below a specific threshold value and substantially constant when a deviation from the lateral offset is below the specific threshold value.   
     
     
         29 . The method according to  claim 28 , wherein the vehicle further comprises a multi-sensor system for, in combination with the 3D underground sonar, collecting the measurement data, the multi-sensor system comprising a plurality of sensors comprising:
 at least one camera,   a side scan sonar device,   a multibeam sonar device,   a front scan sonar device, and   at least one magnetic sensor of a magnetic field detection device,   wherein the method further comprises:   combining the measurement data of at least two of the 3D underground sonar and the multi-sensor system sensors; and   at least one of localizing and examining the object utilizing the combined measurement data.   
     
     
         30 . The method according to  claim 29  further comprising
 surveying, utilizing the collected measurement data, a local surface of the bottom of the body of water below the underwater vehicle; 
 identifying a position of the localized sections of the object relative to the local surface of the bottom of the body of water and 
 classifying, utilizing the identified position, whether the local sections are sections of the object that at least one of rest on the surface of the bottom of the body of water, are buried under the bottom of the body of water, are partially exposed within the bottom of the body of water, and are underwashed within the bottom of the body of water. 
 
     
     
         31 . The method according to  claim 30  further comprising:
 automatically navigating the underwater vehicle utilizing navigation data provided by a navigation means; 
 determining a respective position of the respectively localized section of the object; and 
 assigning at least one of the navigation data and the measurement data to the respective position of the localized section, wherein, for providing the navigation data, the navigation means comprises at least one of:
 a pitch sensor for determining the rotational movement of the underwater vehicle about its transverse axis; 
 
 a roll sensor for determining the rotational movement of the underwater vehicle about its longitudinal axis; 
 a magnetic compass for determining the direction and orientation of the underwater vehicle relative to field lines of the earth's magnetic field; 
 an echo sounder for determining a water depth below the underwater vehicle; 
 an aneroid barometer for determining a water pressure at a depth of the underwater vehicle below the water surface, wherein the determined water pressure is used to determine the depth of the underwater vehicle below the water surface; 
 a device of an “ultra short baseline” underwater navigation system for determining the position using travel time measurements of underwater sound signals to a plurality of other devices in the water; 
 a waterborne sound speed sensor for determining a sound speed in the water; 
 a transponder device for transmitting signals in response to reception of signals; 
 a responder device for transmitting signals in response to the reception of signals; 
 an ultrasonic doppler profile flowmeter for determining a water flow relative to the underwater vehicle; 
 at least one acceleration sensor for determining an acceleration of the underwater vehicle in an inertial reference system; 
 a measuring probe for determining a salt content and a temperature of the surrounding water and for determining a depth of the measuring probe below the water surface; 
 a receiver device for receiving satellite signals of a satellite-assisted navigation system, and for determining the position of the underwater vehicle by means of the satellite signals; and 
 a turbidity sensor for determining a turbidity of the surrounding water. 
 
     
     
         32 . The method according to  claim 31 , further comprising
 three-dimensionally localizing the object utilizing the 3D underground sonar, wherein the underwater vehicle pivots at least one sensor carrier relative to the longitudinal axis of the underwater vehicle and subsequently a plurality of waterborne sound transducers arranged in particular in series, at a plurality of different intervals in each case relative to a pivot axis of the respective sensor carrier, arranged at least in their majority on the sensor carrier, repeatedly determine measurement data and by means of an artificial aperture span an observation surface permitting the three-dimensional localization of the object, wherein the sensor carrier pivots such that for determining the measurement data the waterborne sound transducers have been arranged asymmetrically relative to the longitudinal axis of the underwater vehicle and the waterborne sound transducers subsequently scan a scanning region, the centre thereof having a lateral offset, preferably of at least one metre, to the longitudinal axis of the underwater vehicle.   
     
     
         33 . The method according to  claim 32  further comprising
 planning a mission utilizing a mission planning device, prior knowledge about the position of the object, and 
 producing control data suitable for carrying out the mission and transmitting the control data to the underwater vehicle, subsequently the underwater vehicle independently navigating in the water carries out a submersion manoeuver, wherein
 the underwater vehicle manoeuvers to an operating depth defined by a submerged position, and at the same time repeatedly determines the position of the underwater vehicle, and additionally a surface vessel repeatedly determines the position of the underwater vehicle and transmits said position to the underwater vehicle, and 
 after reaching the operating depth the underwater vehicle performs a “navigation alignment navigation manoeuver” to reach the submerged position, 
 subsequently the underwater vehicle performs a search routine, wherein the underwater vehicle takes into consideration the prior knowledge and after locating the object calculates and traverses a start-up trajectory to a start position, and 
 subsequently the underwater vehicle determines the local object path, follows the object path on its trajectory thereabove, simultaneously examines the object and simultaneously stores detected measurement data in a memory device and subsequently the measurement data stored in the memory device are read and evaluated, wherein at least one of: 
 classification takes place as to whether of the object are sections at least one of rest on the surface of the bottom of the body of water, are buried under the bottom of the body of water, are partially exposed within the bottom of the body of water, and are underwashed within the bottom of the body of water, and 
 the condition of the object is determined. 
 
 
     
     
         34 . The method of  claim 33 , wherein the position of the underwater vehicle is determined utilizing an “ultra short baseline” system.