RESULTS OF TESTING THE POSITIONING ALGORITHM AND DETERMINING THE ORIENTATION OF THE UNDERWATER VEHICLE BASED ON DATA FROM HYDRO-ACOUSTIC BEACONS
Alexander Gruzlikov, Vladislav G. Karaulov, Dmitry Mukhin, Nikita Shalaev · Известия Южного федерального университета. Технические науки · 2023
The article deals with the determination of coordinates and orientation angles of the autonomousunderwater vehicle (AUV) relative to the stationary landing platform using high-frequencynear-range hydroacoustic system. The navigation task implies maneuvering the vehicle and approachingthe underwater station, which is associated with the formation of zones with differentacoustic visibility of the station's emitters by the receiving elements of the vehicle. Three zones ofacoustic visibility can be distinguished. The first zone is characterized by observation of signals of allbeacons of the underwater station. As a consequence, this zone is the most informative for solving theproblem of positioning and orientation determination of the AUV. The second zone corresponds topartial reduction of the number of observed beacons, which does not critically influence the possibilityof problem solving. The third zone (landing) is defined by essential reduction of a number of observedbeacons, that, as consequence, considerably complicates the solution of the positioning problem,taking into account the increased requirements on accuracy at the moment of landing of thedevice caused by provision of safety. To maintain positioning accuracy and determine the underwatervehicle orientation in the landing zone, it is proposed to use the results obtained in the early stages ofapproach of the vehicle to the underwater station (the first and second zones). A mathematical statementof the problem is given in the work, and the algorithm of its solution is described. When findingthe AUV in the first and second zones, the solution algorithm consists of two subtasks. The first subtaskis a rough estimation of location vicinity and angles of vehicle orientation using K-nearestneighbors method; the second subtask is specification of estimations using pseudo-dimensionalmethod by solving system of algebraic equations with Levenberg-Marquardt algorithm. In addition,estimation of beacon emission time is carried out. At finding ANPA in the third zone the algorithm isreduced to solution of system of algebraic equations with use of forecast of time of signal emission bya beacon, received at finding of the device in zones one and two. The results of simulation modelingand results of algorithm approbation obtained using a mockup of the vehicle and a mockup of theunderwater station in the test pool are presented.