An adaptive fuzzy sliding mode controller for the depth control of an underactuated underwater vehicle

Yuan Chen,Yinpo Yan,Kangling Wang,Shuqi Liu

doi:10.1177/1729881419840213

Abstract

An adaptive fuzzy sliding mode controller is proposed for the depth control of an underactuated underwater vehicle based on the state-dependent Riccati equation. An adaptive fuzzy control algorithm is embedded into the sliding mode controller to solve the buffering and mismatched uncertain problems in the robust sliding mode variable structure controller, where an auxiliary fuzzy control unit is designed to automatically adjust the scale factor of the main fuzzy controller output. Based on Lyapunov stability theory and final value bounded theorem, the stability and convergence properties of the closed-loop system are demonstrated. Numerical simulations are carried out to validate the effectiveness of the proposed controller.

Highlights

IntroductionAutonomous underwater vehicles (AUVs) have been widely used to explore ocean resources
Autonomous underwater vehicles (AUVs) have been widely used to explore ocean resources. These vehicles usually contain several critical devices to overcome hazardous underwater environment and to accomplish challenging tasks required for those vehicles
An adaptive fuzzy control algorithm is embedded into the sliding mode controller (SMC) to solve the buffering and mismatched uncertain problems in the robust sliding mode variable structure controller, where an auxiliary fuzzy control unit is designed to automatically adjust the scale factor of the main fuzzy controller output

Summary

Introduction

Autonomous underwater vehicles (AUVs) have been widely used to explore ocean resources. Ma et al.[4] designed an adaptive sliding mode dynamical surface controller for a hybrid unmanned aerial underwater vehicles. Zhang et al.[6] proposed an adaptive quasi-sliding mode control method for the path following system of an underactuated unmanned underwater vehicle. Bessa et al.[7] presented an adaptive fuzzy sliding mode controller (AFSMC) for remotely operated underwater vehicles. An adaptive fuzzy control algorithm is embedded into the SMC to solve the buffering and mismatched uncertain problems in the robust sliding mode variable structure controller, where an auxiliary fuzzy control unit is designed to automatically adjust the scale factor of the main fuzzy controller output. Can be simplified as the following compact form by ignoring the sufficiently small second-order viscous damping coefficient x_ 1⁄4 Ax þ Bu þ d ð3Þ where d denotes the unmodeled dynamics and external interference and it is a matrix of four rows and one column; the matrix A is equal with T À1A0 , and the input matrix B is equal with

Z uw u

À0:0722 3 0:1 Â sin t 0 0 0

Conclusions