... equations were solved using commercial CFD software Star CCM+ coupled with two degrees of freedom solid body motion equations, including heave and pitch. The self-propulsion point is determined by autonomously adjusting the propeller rotational speed with a PID controller to balance the total ship...

... the wave effects. Effects of ship speed and heading control were also discussed. It was found that the propeller model had little effect on ship added resistance and motion responses. The rudder controller introduced significant low-frequency components to roll and yaw motion. Compared with EFD, the CFD...

... by a Proportional (P) and Proportional Integral (PI) IM controller in the peak wave frequency of the design sea state, equivalent to a resistive and reactive controller, respectively. These causal IM controllers are implemented in a MATLAB-Simulink real-time control environment and experimentally tested...

... ABSTRACT In this paper, a damping adaptable passive heave compensation system for a 600 meters shipwreck salvaging claw and the corresponding control algorithm are proposed. Salvaging claw is a new method for entirely salvaging shipwrecks. Passive heave compensation is added between the vessel...

... ABSTRACT This paper proposes a novel robust fixed-time control scheme based on a fixed-time disturbance observer for the dynamically positioned semi-submersible platform subject to wave loadings. The control law is designed aiming at resisting the low-frequency motions with the help...

... ABSTRACT This paper presents a high-precision underwater depth measurement system based on multi-sensor data fusion and the Kalman filter algorithm to effectively improve the accuracy and reliability of underwater depth measurement. The system is controlled by PID controller and Kalman filter...

... ABSTRACT This paper proposes a new algorithm for the floating of the underwater platform. To eliminate the effect of the disturbance and improve the safety of the floating process, a fuzzy PID algorithm with a nonlinear feedback technique is used to control the underwater platform. Compared...

... ABSTRACT In order to prevent the uncontrollable influence of residual buoyancy and residual torque on the motion control of AUV, a depth control method of AUV under unbalanced state is proposed. The control system is mainly composed of three parts: imbalance estimation algorithm, depth...

... ABSTRACT This paper presents an augmented model predictive control (AMPC) method to enhance the motion control performance of the remotely operated underwater vehicle (ROV) with saturation limits and external disturbance. The incremental form prediction model is utilized to design the new...

... ABSTRACT Work-class ROVs are always subject to external disturbances and system uncertainties. The sliding mode control is an effective method to overcome the disturbances, but its chattering phenomenon restricts its practical application on ROVs. In this paper, we propose a model-free...

... ABSTRACT In this paper, the speed control strategy of a large inertia underwater vehicle with flexible cable traction is studied. The system consists of two winches directly driven by electric motors, two wire ropes and an underwater vehicle installed on a linear guide device. The model...

... ABSTRACT This paper proposes a dynamic control assignment method for X-rudder intelligent underwater vehicle based on sliding mode fault observer. Firstly, the adaptive PID controller is designed, and the heeling moment, trim moment and yaw moment of the virtual control instruction...

... ABSTRACT This paper introduces the causes and effects of the air cushion, and proposes a balanced control scheme for the negative effects of the air cushion. A depth-tip dual-closed loop rudder angle controller combined with variable line-of-sight angle guidance method and variable speed...

... Deep Deterministic Policy Gradient (MTD3) algorithm is adapted to train a controller for obstacle avoidance. A Markov decision process model including state, action, and reward functions is designed, and a suitable reinforcement-learning training environment is designed. The obstacle-avoidance ability...

... ABSTRACT This paper presents results from the Floating Offshore-wind Controls Advanced Laboratory (FOCAL) Experimental campaign performed at the University of Maine's (UMaine's) Harold Alfond Wind/Wave Ocean Engineering Laboratory (W 2 ). The project involves four Froude-scaled test campaigns...

... ABSTRACT The coupled action of wind and wave on the stability of floating offshore wind turbines (FOWT) tremendously affects the lifespan of these energy systems and their energy output. Passive control systems reduce such loads but can only mitigate the loading over a small range...

... converter still operates at low voltage (LV) at the generator side while the outputs are connected in series to match the medium voltage (MV) grid. The paper discusses the control schemes for the power converter and presents the operational results using MATLAB/SIMULINK software. INTRODUCTION Reducing...

... ABSTRACT To guarantee high-accuracy platform pose control and the feasibility of the cable tension distribution, a linear model prediction control-based method for cable driven parallel mechanism is proposed in this paper. Moreover, the X-swapping method is used to linearize and identify...

... ABSTRACT To get better performance of ship path following control under the line-of-sight (LOS) strategy with proportional-integral-derivative (PID) control method, three PID tune methods are introduced and carried out based on real experiments. During the PID tune process, the advantages...

... be actuated or moved by a pump to counteract effects of the wave-induced forces and moments on the float, on the basis of some control law. Here we present the development and experimental validation of a control system based on real-time simulations of the wave-induced motions of a floating object, with its...