Correction Algorithm for the Navigation System of an Autonomous Unmanned Underwater Vehicle.

Danhe Chen,K A Neusypin,M S Selezneva

doi:10.3390/s20082365

Abstract

More accurate navigation systems are always required for autonomous unmanned underwater vehicles (AUUV)s under various circumstances. In this paper, a measuring complex of a heavy unmanned underwater vehicle (UUV) was investigated. The measuring complex consists of an inertial navigation platform system, a Doppler lag (DL) and an estimation algorithm. During a relatively long-term voyage of an UUV without surfacing and correction from buoys and stationary stations, errors of the measuring complex will increase over time. The increase in errors is caused by an increase in the deviation angles of the gyro platform relative to the accompanying trihedron of the selected coordinate system. To reduce these angles, correction is used in the structure of the inertial navigation system (INS) using a linear regulator. To increase accuracy, it is proposed to take into account the nonlinear features of INS errors; an adaptive nonlinear Kalman filter and a nonlinear controller were used in the correction scheme. Considering that, a modified nonlinear Kalman filter and a regulator in the measuring complex are proposed to improve the accuracy of the measurement information, and modification of the nonlinear Kalman filter was performed through a genetic algorithm, in which the regulator was developed by the State Dependent Coefficient (SDC) method of the formulated model. Modeling combined with a semi-natural experiment with a real inertial navigation system for the UUV demonstrated the efficiency and effectiveness of the proposed algorithms.

Highlights

For performing underwater work as scientific research and practical implementation, unmanned underwater vehicles (UUV)s are widely used
A set of algorithms was developed for measuring complex (MC), including a nonlinear control algorithm that was used for error compensation in the structure of inertial navigation systems (INS), and they can work for a long time without correction from stationary navigation stations
The MC consists of an INS platform, Doppler lag, nonlinear Kalman filter (NKF) of modified genetic algorithm (GA), and a nonlinear controller for correction in the structure of INS

Summary

Introduction

For performing underwater work as scientific research and practical implementation, unmanned underwater vehicles (UUV)s are widely used. UUVs can be classified according to the mass of the vehicle: micro, small, medium and heavy classes [3,4]. For the study of ice conditions, the performance of hydrographic work in the Arctic, as well as the fulfillment of special tasks in the interests of defense agencies, heavy autonomous unmanned underwater vehicles (AUUV)s (not towed UUVs) are applied. During the operation of UUVs, their exact orientation in space and knowledge of navigation parameters are very important. For this purpose, inertial navigation systems (INS), sonars, Doppler lags, etc., are installed on AUUVs [5,6,7]. The UUV GAVIA is equipped with a strapdown INS and the Sensors 2020, 20, 2365; doi:10.3390/s20082365 www.mdpi.com/journal/sensors

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Conclusion