Browsing NTNU Open by Author "Han, Xu"
Now showing items 1-14 of 14
-
Adaptive identification of lowpass filter cutoff frequency for online vessel model tuning
Han, Xu; Ren, Zhengru; Leira, Bernt Johan; Sævik, Svein (Peer reviewed; Journal article, 2021)Tuning of vessel models in real-time based on vessel measurements and weather information is of great interest in order to increase the safety and efficiency of marine operations. Vessel motion signals usually contain ... -
Analyzing the Sensitivity of Wave Frequency Responses of Floating Vessels to Uncertain System Variables Utilizing Polynomial Chaos Expansion
Radhakrishnan, Gowtham; Leira, Bernt Johan; Gao, Zhen; Sævik, Svein; Han, Xu (Peer reviewed; Journal article, 2023)From a mathematical viewpoint, the frequency domain analysis of vessel motion responses due to wave actions is based on integration of system dynamics idealized in terms of response amplitude operators for six degrees-of-freedom ... -
Data-driven simultaneous identification of the 6DOF dynamic model and wave load for a ship in waves
Ren, Zhengru; Han, Xu; Yu, Xingji; Skjetne, Roger; Leira, Bernt Johan; Sævik, Svein; Zhu, Man (Peer reviewed; Journal article, 2023)In marine operations, the performance of model-based automatic control design and decision support systems highly relies on the accuracy of the representative mathematical models. Model fidelity can be crucial for safe ... -
A Framework for Condition Monitoring and Risk-Based Decision Support Involving a Vessel State Observer
Han, Xu; Leira, Bernt Johan; Sævik, Svein; Radhakrishnan, Gowtham; Skjong, Stian; Kyllingstad, Lars Tandle (Chapter, 2021)Digital twins have attracted significant attention across different domains for decades. In the maritime and the energy industries, digital twins have been mainly used for system condition monitoring, project visualization, ... -
Modal Parameter Identification of Jacket-Type Offshore Wind Turbines Under Operating Conditions
Zhang, Chen; Han, Xu; Li, Chunhao; Leira, Bernt Johan; Sævik, Svein; Lu, Dongzhe; Shi, Wei; Li, Xin (Journal article; Peer reviewed, 2024)Operational modal analysis (OMA) is essential for long-term health monitoring of offshore wind turbines (OWTs), helping identifying changes in structural dynamic characteristics. OMA has been applied under parked or idle ... -
Onboard Tuning and Uncertainty Estimation of Vessel Seakeeping Model Parameters
Han, Xu (Doctoral theses at NTNU;2021:356, Doctoral thesis, 2021)The accurate prediction of critical vessel motions is essential for safe and cost-efficient marine operations. Compared with the difference-frequency responses that can be compensated by mooring and dynamic positioning ... -
Onboard tuning of vessel seakeeping model parameters and sea state characteristics
Han, Xu; Leira, Bernt Johan; Sævik, Svein; Ren, Zhengru (Peer reviewed; Journal article, 2021)It is essential for a safe and cost-efficient marine operation to improve the knowledge about the real-time onboard vessel conditions. This paper proposes a novel algorithm for simultaneous tuning of important vessel ... -
Sea state estimation based on vessel motion responses: Improved smoothness and robustness using Bezier surface and L1 optimization
Ren, Zhengru; Han, Xu; Verma, Amrit Shankar; Dirdal, Johann Alexander; Skjetne, Roger (Peer reviewed; Journal article, 2021)Floating structures oscillate in waves, where these wave-induced motions may be critical for various marine operations. An important consideration is thereby given to the sea states at the planning and operating stages for ... -
A Sensitivity Study of Vessel Hydrodynamic Model Parameters
Han, Xu; Sævik, Svein; Leira, Bernt Johan (Chapter, 2020)In the recent decade, maritime and energy industries have realized the potential of using operational data in combination with a virtual replication of the real physical asset, termed the digital twin. The digital twin ... -
System Uncertainty Effects on the Wave Frequency Response Of Floating Vessels Based on Polynomial Chaos Expansion
Radhakrishnan, Gowtham; Han, Xu; Sævik, Svein; Gao, Zhen; Leira, Bernt Johan (Chapter, 2021)From a mathematical viewpoint, the frequency domain analysis of vessel motion responses due to wave actions incorporates the integration of system dynamics idealized in terms of response amplitude operators (RAOs) for 6 ... -
System Uncertainty Effects on the Wave Frequency Response of Floating Vessels Based on Polynomial Chaos Expansion
Radhakrishnan, Gowtham; Han, Xu; Sævik, Svein; Gao, Zhen; Leira, Bernt Johan (Peer reviewed; Journal article, 2021)From a mathematical viewpoint, the frequency domain analysis of vessel motion responses due to wave actions incorporates the integration of system dynamics idealized in terms of response amplitude operators (RAOs) for 6 ... -
Tuning of vessel parameters including sea state dependent roll damping
Han, Xu; Sævik, Svein; Leira, Bernt Johan (Peer reviewed; Journal article, 2021)Online tuning of vessel models based on onboard measurement data can reduce the uncertainties of vessel motion prediction, and therefore potentially increase the safety and cost efficiency for marine operations. Among the ... -
Validation of vessel seakeeping model tuning algorithm based on measurements at model scale
Han, Xu; Leira, Bernt Johan; Sævik, Svein; Kaasen, Karl Erik (Peer reviewed; Journal article, 2021)Wave-induced vessel motion prediction plays a critical role in ensuring safe marine operations. The operational limiting criteria can usually be calculated by applying presumed linearized vessel motion transfer functions ... -
Vessel hydrodynamic model tuning by Discrete Bayesian updating using simulated onboard sensor data
Han, Xu; Leira, Bernt Johan; Sævik, Svein (Peer reviewed; Journal article, 2021)Vessel and wave hydrodynamics are fundamental for vessel motion prediction. Improving hydrodynamic model accuracy without compromising computational efficiency has always been of high interest for safe and cost-effective ...