Nonlinear-Observer-Based Design Approach for Adaptive Event-Driven Tracking of Uncertain Underactuated Underwater Vehicles

Jin Hoe Kim,Sung Jin Yoo

doi:10.3390/math9101144

Abstract

A nonlinear-observer-based design methodology is proposed for an adaptive event-driven output-feedback tracking problem with guaranteed performance of uncertain underactuated underwater vehicles (UUVs) in six-degrees-of-freedom (6-DOF). A nonlinear observer using adaptive neural networks is presented to estimate the velocity information in the presence of unknown nonlinearities in the dynamics of 6-DOF UUVs where a state transformation approach using a time-varying scaling factor is introduced. Then, an output-feedback tracker using a nonlinear error function and estimated states is recursively designed to overcome the underactuated problem of the system dynamics and to guarantee preselected control performance in three-dimensional space. It is shown that the tracking error of the nonlinear-observer-based output-feedback control system exponentially converges a small neighbourhood around the zero. Efficiency of the resulting output-feedback strategy is verified through a simulation.

Highlights

Over the past few decades, the development of advanced control strategies has stimulated interest in the control field of autonomous underwater vehicles [1]
In [9], a combined problem of trajectory planning and tracking control was addressed for underactuated underwater vehicles (UUVs) on the horizontal plane
To manage the transmission signal data economically, some limited studies have tried to deal with the event-triggered full state-feedback design problems for the depth control of underwater vehicles [28] and the prescribed performance control of 6-DOF UUVs [23]

Summary

Introduction

Over the past few decades, the development of advanced control strategies has stimulated interest in the control field of autonomous underwater vehicles [1]. To manage the transmission signal data economically, some limited studies have tried to deal with the event-triggered full state-feedback design problems for the depth control of underwater vehicles [28] and the prescribed performance control of 6-DOF UUVs [23]. (ii) Compared with the existing event-triggered control results for three-dimensional tracking [23,28], this study establishes the design methodology of the guaranteedperformance-based adaptive tracker and its event-triggering condition depending on only the position measurement of 6-DOF UUVs. the stability of the proposed output-feedback event-triggered tracking system is analyzed in the Lyapunov sense.

Problem Formulation

Adaptive Nonlinear Observer Design Using Neural Networks

Output-Feedback Event-Driven Controller Design and Stability Analysis

Simulation Examples

Findings

Conclusions