Ronghui Li

Active Disturbance Rejection with Sliding Mode Control Based Course and Path Following for Underactuated Ships

The compound control of active-disturbance-rejection control (ADRC) with sliding mode is proposed to improve the performance of the closed-loop system and deal with the constraint condition problem of a surface ship. The advantages of ADRC with sliding mode were verified by ship course control simulations. Meanwhile, to solve the path-following problem of underactuated surface ships with uncertainties of internal dynamic and external disturbances, the ADRC controller with sliding mode is introduced to steer the ship to follow the desired path. In order to overcome the cross-track error caused by wind and current, drift angle is compensated in the controller by designing a coordinate transformation equation. Simulations were performed on a nonlinear kinematics model of a training ship to validate the stability and excellent robustness of the proposed path-following controller.

Active disturbance rejection control on path following for underactuated ships

To solve the path following problem of underactuated surface ships with internal dynamic uncertainties and external disturbances, an Active-Disturbance-Rejection Control (ADRC) controller is introduced to steer the ship to follow the desired path. Drift angle compensation is added to the controller by designing a coordinate transformation equation. The cross track static error caused by wind and current is overcome. Simulations were carried out on a fully nonlinear hydrodynamic model of a training ship to validate the stability and excellent robustness of the proposed controller.

Ship tracking control based on linear active disturbance rejection control

Owing to ships high inertia, strong time lag, non-linearity and under-actuated characteristics, as well as sustaining external disturbances frequently, designing a high performance ship tracking controller is still one of the most important research topics of ship motion control. Active Disturbance Rejection Control (ADRC) is proved to be very effective control method because it is independent of mathematical model of the plant and can compensate the internal and external disturbances dynamically. This paper investigates the applications of ADRC in ship motion tracking control and presents the design method of ADRC controller appropriate for ship tracking control. Firstly, ship motion mathematical model is introduced briefly and the linear ADRC (LADRC) is analyzed. Then considering the nonlinear ship track design model as a third order plant after utilizing variable substitution, a LADRC controller is designed by using fourth order linear extended state observer (LESO). At last, the simulation is performed. Simulation results show that the controller has a good tracking performance and disturbance rejection ability and is robust to the ship motion nonlinear characteristic and the external disturbances. The tracking process is fast, smooth and minor energy consumption.

ADRC-Based Ship-Track Control and Its Application to Traffic Safety Evaluation in Harbor Fairway

This paper investigates the control design of a novel ship-track controller, i.e., an active-disturbance-rejection-control (ADRC)-based ship-track autopilot, and its application to the traffic safety evaluation in harbor fairway. Firstly, a robust adaptive autopilot for ship track control is developed based on ADRC, which is a model-free controller and performs with minor control energy, strong robustness and easy implementation. Then, a new ship traffic safety evaluation methodology is proposed, where an impersonal and advising strategy of ship safe maneuvering action in the investigated fairway can be further achieved. The comparing simulation results demonstrate the effectiveness of the proposed method.