Performance-Guaranteed Tracking Control of an Autonomous Surface Vessel With Parametric Uncertainties and Time-Varying Disturbances

Chao Dong,Shi-Lu Dai,Shude He

doi:10.1109/access.2019.2931337

Abstract

In this paper, the model-based adaptive control combined with a continuous robust integral of the sign of the error (RISE) feedback strategy is presented for the trajectory tracking control of an autonomous surface vessel (ASV) subject to parametric uncertainties and time-varying disturbances. The control objective is to achieve asymptotic tracking and guarantee the transient tracking performance simultaneously. An adaptive feedforward term is used to compensate for the parametric uncertainties, and the effects generated by external disturbances can be overcome by a gain of the error sign term (a part of the RISE feedback term). In the previous RISE-based feedback control, the upper bounds of disturbances and their time derivatives are often required to be known, while the requirement is relaxed, in this paper, by rendering the gain of the error sign term adaptive. It should be noted that the adaptive gain of the error sign term adjusts automatically until it is sufficient to compensate for the disturbances, which helps to reduce the control effort. Moreover, the prescribed performance control technique is introduced to provide the transient performance specification of the tracking error, which guarantees the tracking performance and improves the robustness of the control system. Based on the backstepping procedure and the Lyapunov stability analysis, asymptotic trajectory tracking with transient tracking performance is theoretically guaranteed, and all the signals are shown to be bounded. The effectiveness of the proposed control scheme is demonstrated through the numerical simulation results.

Highlights

Over the past decades, the nonlinear motion control theory of autonomous surface vessel (ASV) has received considerable attention in marine technology and control engineering motivated by its extensive applications such as transportation, environmental surveying, monitoring, and many other military and commercial applications [1]–[4]
We address the problem of asymptotic trajectory tracking with guaranteed transient tracking performance for an ASV despite the presence of parametric uncertainties and time-varying disturbances
To achieve asymptotic convergence of the trajectory tracking error, the RISE feedback control strategy incorporated with model-based adaptive feedforward term is introduced to deal with parametric uncertainties and external disturbances

Summary

INTRODUCTION

The nonlinear motion control theory of autonomous surface vessel (ASV) has received considerable attention in marine technology and control engineering motivated by its extensive applications such as transportation, environmental surveying, monitoring, and many other military and commercial applications [1]–[4]. To achieve asymptotic convergence of the trajectory tracking error, the RISE feedback control strategy incorporated with model-based adaptive feedforward term is introduced to deal with parametric uncertainties and external disturbances. The condition that generally requires a prior knowledge for the upper bounds of disturbances and their time derivatives in the previous RISE-based feedback control has been relaxed by rendering the gain of the error sign term adaptive through an update rule, which reduces the control effort to compensate for the disturbances. (2) The gain of the error sign term is rendered adaptive to compensate for the disturbances through an update rule, which brings benefit that the prior knowledge of the upper bounds of disturbances and their time derivatives often required in the previous RISE-based feedback control scheme [15]–[18] is no longer needed.

STABILITY ANALYISIS

NUMERICAL SIMULATION

CONCLUSION