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This dataset is collected from a laboratory scale floating offshore wind turbine with mooring systems. The wave data as well as the 6DoF platform motion data are collected by the wave gauges and Qualisys motion capture system, respectively.  Three wave conditions are considered.  More details please refer to the PDF documentation. 

This dataset is collected from a lab scale gear system.  The experiments are conducted across 9 different fault conditions and three load conditions with 6 different sensor locations.  More details can be found in the word documentation. 

This paper introduces a simulation framework and a corresponding Robust Optimal Control (ROC) for docking Unmanned Underwater Vehicles (UUVs) that leverages Marine Renewable Energy (MRE) for improved autonomy in docking and charging operations. The proposed simulation framework integrates the dynamics of the Wave Energy Converter (WEC), docking station, and UUV within a unified system. Utilizing the WEC-Sim for the hydrodynamic modeling and MoorDyn for mooring dynamics, and in-house UUV dynamics in Simulink, the simulation effectively accounts for complex interactions under dynamic ocean conditions. The ROC docking controller, consisting of a Linear Quadratic Regulator (LQR) and a Sliding Mode Control (SMC), is designed to enhance robustness against environmental disturbances and system uncertainties. This controller utilizes input-output linearization to transform the nonlinear dynamics into a manageable linear form, optimizing docking performance while compensating for disturbances and uncertainties. The combined simulation and control approach is validated under various ocean conditions, demonstrating effective docking precision and energy efficiency. This work lays a foundational platform for future advancements in autonomous marine operations for UUV docking systems integrated with WEC. In addition, this work also demonstrates the feasibility of using MRE to significantly extend the operational duration of UUVs; such a platform will be leveraged for further development of structural health monitoring and fault diagnosis techniques for offshore structures such as WECs and Floating Offshore Wind Turbines. 

A novel Variable-Shape Buoy Wave Energy Converter (VSB WEC) that aims at eliminating the requirement of reactive power is analyzed in this paper. Unlike conventional Fixed Shape Buoy Wave Energy Converters (FSB WECs), the VSB WEC allows continuous shape-changing (flexible) responses to ocean waves. The non-linear interaction between the device and waves is demonstrated to result in more power when using simple, low-cost damping control system. High fidelity numerical simulations are conducted to compare the performance of a VSB WEC to a conventional FSB WEC, of the same volume and mass, in terms of power conversion, maximum displacements, and velocities. A Computational Fluid Dynamics (CFD) based Numerical Wave Tank (CNWT), developed using ANSYS 2-way fluid-structure interaction (FSI) is used for simulations. The results show that the average power conversion is significantly increased when using the VSB WEC. 

The wave excitation force is required in some control algorithms of wave energy converters. Excitation force is not, however, directly measurable. Therefore, to obtain excitation force information for control implementation, a number of excitation force estimators have been developed. The estimation performance is usually validated by low-fidelity simulations. This paper assesses the performance of a wave estimator in a Computational Fluid Dynamics (CFD) based Numerical Wave Tank (CNWT), where the estimator collects necessary measurements in-line with the high-fidelity simulation. The proposed simulation framework can be directly applied for a controlled wave energy converter. Numerical simulations are conducted on the implemented estimator, and the estimated excitation force is compared with a benchmark force that is extracted from a diffraction test. 

This paper derives a control law within the context of optimal control theory for a heaving wave energy converter (WEC) and presents its implementation procedure. The proposed control assumes the availability of measurements of pressure distribution on the buoy surface, buoy position, and buoy velocity. This control has two main characteristics. First, this control is derived based on a simple dynamic model. The forces on the WEC are modeled as one total force, and hence there is no need to compute excitation or radiation forces. Second, this control can be applied to both linear and nonlinear WEC systems. The derived control law is optimal, yet its implementation requires estimation of some force derivatives which render the obtained control force sub-optimal. Numerical testing demonstrates in this paper that the proposed simple model control can achieve levels of harvested energy close to the maximum theoretical limit predicted by singular arc control in the case of linear WEC systems.