NONLINEAR ROBUST CONTROL SYSTEM FOR STABILIZATION OF MARINE VEHICLES

Nonlinear Control and Robust Observer Design for Marine Vehicles

A robust nonlinear observer, utilizing the sliding mode concept, is developed for the dynamic positioning of ships. The observer provides the estimates of linear velocities of the ship and bias from the slowly varying environmental loads. It also filters out wave frequency motion to avoid wear of actuators and excessive fuel consumption. Especially, the observer structure with a saturation func...

Nonlinear Robust Tracking Control of an Underwater Vehicle-Manipulator System

This paper develops an improved robust multi-surface sliding mode controller for a complicated five degrees of freedom Underwater Vehicle-Manipulator System with floating base. The proposed method combines the robust controller with some corrective terms to decrease the tracking error in transient and steady state. This approach improves the performance of the nonlinear dynamic control scheme a...

Limitations of nonlinear periodic sampled-data control for robust stabilization

This paper presents a performance analysis of nonlinear periodically time varying sampled-data controllers acting upon a linear time invariant plant. Time invariant controllers are distinguished from strictly periodically time varying controllers. For a given nonlinear strictly periodic controller, a time invariant controller is constructed. Necessary and sufficient conditions are given under w...

A Nonlinear Vision Based Tracking System for Coordinated Control of Marine Vehicles

A nonlinear vision based tracking system is developed to provide estimates of the position and velocity of an Autonomous Underwater Vehicle (AUV) relative to an Autonomous Surface Craft (ASC). Nonlinear estimator design builds on the theory of linear parametrically varying (LPV) systems. The theoretical framework adopted provides a powerful tool for estimator regional stability and performance ...

Robust Takagi-Sugeno sensor fault tolerant control strategy for nonlinear system