Autonomous Underwater Vehicles

Modeling, Control Design and Simulation

Sabiha Wadoo, Pushkin Kachroo

• Publisher: CRC Press
• Year: 2017
• Print ISBN: 9781439818312
• eBook ISBN: 9781351833929
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

Underwater vehicles present some difficult and very particular control system design problems. These are often the result of nonlinear dynamics and uncertain models, as well as the presence of sometimes unforeseeable environmental disturbances that are difficult to measure or estimate.

Autonomous Underwater Vehicles: Modeling, Control Design, and Simulation outlines a novel approach to help readers develop models to simulate feedback controllers for motion planning and design. The book combines useful information on both kinematic and dynamic nonlinear feedback control models, providing simulation results and other essential information, giving readers a truly unique and all-encompassing new perspective on design.

Includes MATLAB® Simulations to Illustrate Concepts and Enhance Understanding

Starting with an introductory overview, the book offers examples of underwater vehicle construction, exploring kinematic fundamentals, problem formulation, and controllability, among other key topics. Particularly valuable to researchers is the book's detailed coverage of mathematical analysis as it applies to controllability, motion planning, feedback, modeling, and other concepts involved in nonlinear control design. Throughout, the authors reinforce the implicit goal in underwater vehicle design—to stabilize and make the vehicle follow a trajectory precisely.

Fundamentally nonlinear in nature, the dynamics of AUVs present a difficult control system design problem which cannot be easily accommodated by traditional linear design methodologies. The results presented here can be extended to obtain advanced control strategies and design schemes not only for autonomous underwater vehicles but also for other similar problems in the area of nonlinear control.

1 Introduction

1.1 Overview

The work presented in this book is concerned with developing models that can be used for the motion planning and feedback control design of underwater vehicles. Underwater vehicles present difficult control system design problems due to their nonlinear dynamics, uncertain models, and the presence of disturbances that are difficult to measure or estimate. Many problems must be solved to make robotic underwater vehicles a reality. The dynamic control of the vehicle needs to guarantee stability and perform consistently. The dynamics of autonomous underwater vehicles present a difficult control system design problem that traditional linear design methodologies cannot accommodate easily. The dynamics are fundamentally nonlinear in nature. Hydrodynamic coefficients often are poorly known, and a variety of immeasurable disturbances are present due to currents.

In this book, a new approach of feedback control methodology is developed to the accurate trajectory control and point stabilization of underwater vehicles. The feedback control is developed in both the absence and presence of uncertainties. The methods can deal with nonlinear dynamics directly, and are shown to be stable in the presence of disturbances, thereby making the control robust.

The first part of the book presents the study concerning the applicability of kinematic-based control of underwater vehicles. The methods of motion planning and feedback control for a kinematic model of an underwater vehicle are developed. The kinematic model of an underwater vehicle falls into a general category of nonholonomic systems. The system is characterized by nonholonomic constraints on its generalized velocities. The motion planning problem for this system, with constraints on the velocities, is transformed into a control problem having fewer control inputs than the degrees of freedom. The nonlinear controllability issues for the system are also studied. For the design of feedback controllers, the system is transformed into chained and power forms. The methods of transforming the kinematic model of the system into these forms are discussed. Differential geometric control theory and nonlinear system analysis and control design techniques, and the results of recent research and study in the motion planning of nonholonomic systems are used and presented for the support of the work.

The kinematic model of the autonomous underwater vehicle is developed, and the feedback controller design for the same is presented in detail and simulation results are obtained. Also, a brief mathematical analysis of the concepts involved in the study of controllability, control design, and modeling is presented.

The kinematic-based control addresses the motion planning for a kinematic model of an underwater vehicle. The kinematic model belongs to nonholonomic systems. The control...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Preface
• About the Authors
• Chapter 1 Introduction
• Chapter 2 Problem Formulation and Examples
• Chapter 3 Mathematical Modeling and Controllability Analysis
• Chapter 4 Control Design Using the Kinematic Model
• Chapter 5 Control Design Using the Dynamic Model
• Chapter 6 Robust Feedback Control Design
• References
• Index