Browsing NTNU Open by Author "Ren, Zhengru"
Now showing items 1-20 of 46
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A Crane Overload Protection Controller for Blade Lifting Operation Based on Model Predictive Control
Ren, Zhengru; Skjetne, Roger; Gao, Zhen (Journal article; Peer reviewed, 2019)Lifting is a frequently used offshore operation. In this paper, a nonlinear model predictive control (NMPC) scheme is proposed to overcome the sudden peak tension and snap loads in the lifting wires caused by lifting speed ... -
A parametric study on the final blade installation process for monopile wind turbines under rough environmental conditions
Jiang, Zhiyu; Gao, Zhen; Ren, Zhengru; Li, Ye; Duan, Lei (Journal article; Peer reviewed, 2018)Single blade installation is a method for installing wind turbine blades. If a jack-up vessel is used during an o shore installation, the wind turbine blade is mainly subjected to wind loads and experiences resonant motions, ... -
A Summary of the Recent Work at NTNU on Marine Operations Related to Installation of Offshore Wind Turbines
Gao, Zhen; Verma, Amrit Shankar; Zhao, Yuna; Jiang, Zhiyu; Ren, Zhengru (Chapter, 2018)In this paper, a summary of the recent work at NTNU on the installation of offshore wind turbines using jack-up and floating vessels will be reported. The wind turbine components considered here are the monopile foundations ... -
A Tension-based Position Estimation Approach for Moored Marine Vessels
Ren, Zhengru; Skjetne, Roger; Kjerstad, Øivind Kåre (10th IFAC Conference on Manoeuvring and Control of Marine Craft;MCMC 2015, Journal article; Peer reviewed, 2015)This paper presents a novel idea on a tension-based localization approach as a redundancy measure to handle the situation when the position reference (posref) signals are not available or significant GNSS drifts occur, ... -
Active heave compensation of floating wind turbine installation using a catamaran construction vessel
Ren, Zhengru; Skjetne, Roger; Verma, Amrit Shankar; Jiang, Zhiyu; Gao, Zhen; Halse, Karl Henning (Peer reviewed; Journal article, 2021)The application of floating wind turbines is limited by the high cost that increases with the water depth. Offshore installation and maintenance continue to consume a high percentage of the project budget. To improve the ... -
Active Single-Blade Installation Using Tugger Line Tension Control and Optimal Control Allocation
Ren, Zhengru; Skjetne, Roger; Jiang, Zhiyu; Gao, Zhen (Peer reviewed; Journal article, 2020)The single-blade installation is a common method for the installation of wind turbine blades. In an offshore installation, a jackup vessel is often involved, and a crane is used to lift, move, and bolt each blade onto the ... -
Active tugger line force control for single blade installation
Ren, Zhengru; Jiang, Zhiyu; Gao, Zhen; Skjetne, Roger (Journal article, 2018)Single blade installation is one of the methods for installing large wind turbine blades at an offshore site. During this installation, each blade is lifted by the main crane from the deck of an installation vessel or a ... -
Adaptive Backstepping Control of Ship Speed Tracking and Hybrid Mode Selection.
Gao, Fan; Brodtkorb, Astrid H.; Mo, Sigrid Marie; Ren, Zhengru; Sørensen, Asgeir Johan (Peer reviewed; Journal article, 2021)This paper investigates the application of adaptive backstepping control to a hybrid power system for ship propulsion, using a main diesel engine in conjunction with a battery for auxiliary power supply. Fuel injection ... -
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 ... -
Advanced Control Algorithms to Support Automated Offshore Wind Turbine Installation
Ren, Zhengru (Doctoral theses at NTNU;2019:231, Doctoral thesis, 2019)The thesis presents the research on automated offshore wind turbine (OWT)installation. The aim of the project is to find innovative and cost-effective methods for installing and maintaining OWTs. Utilization of wind ... -
An On-site Current Profile Estimation Algorithm for a Moored Floating Structure
Ren, Zhengru; Skjetne, Roger (Journal article; Peer reviewed, 2016)The current speed influences the safety of subsea and marine operations. This paper proposes an algorithm to estimate the depth-dependent current profile though data from existing commercial sensors, that is the mooring ... -
Current Profile Estimation for a Moored Floating Structure
Lu, Ying (Master thesis, 2018)Stationkeeping operations for offshore vessels (drillrigs, drillships, construction and intervention vessels, PSVs, etc.) are essential for offshore filed development and oil and gas production. Short-term subsea operations ... -
Damage identification of a jacket support structure for offshore wind turbines
Jiang, Zhiyu; Bjørnholm, Marius; Guo, Jiamin; Dong, Wenbin; Ren, Zhengru; Verma, Amrit Shankar (Chapter, 2020)Offshore jacket structures are regarded as a suitable type of support structure for offshore wind turbines in immediate water depths. Because of the welded tubular members used and environmental conditions, offshore jackets ... -
Data-driven sea state estimation for a DP vessel based on distributed inertial measurement units
Slåttum, Sindre Sagsveen (Master thesis, 2021)I denne oppgaven blir en metode for å estimere parameterne i en sjøtilstand baser på akselerasjonsmålinger fra et skip på dynamisk posisjonering, uten foroverhastighet. IMU sensurere fordelt rundt i skipet gjør det mulig ... -
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 ... -
Development and application of a simulator for offshore wind turbine blades installation
Ren, Zhengru; Jiang, Zhiyu; Skjetne, Roger; Gao, Zhen (Journal article, 2018)In an offshore environment, offshore wind energy resources are more available and stable, but the investment cost is much higher than that of onshore wind. The installation cost is a crucial factor of the investment. With ... -
Dynamic Simulation and Control of an Active Roll Reduction System Using Free-Flooding Tanks With Vacuum Pumps
Xu, Jiafeng; Ren, Zhengru; Li, Yue; Skjetne, Roger; Halse, Karl Henning (Journal article; Peer reviewed, 2018)Ship roll motion is critical for offshore operations due to its lack of damping mechanism. This paper demonstrates a dynamic simulation scheme of an active roll reduction system using free-flooding tanks controlled by ... -
Dynamic Simulation and Control of an Active Roll Reduction System Using Free-Flooding Tanks With Vacuum Pumps
Xu, Jiafeng; Ren, Zhengru; Li, Yue; Skjetne, Roger; Halse, Karl Henning (Chapter; Peer reviewed, 2017)Ship roll motion is often the critical factor for offshore operations due to its lack of damping mechanism. This paper demonstrates a dynamic simulation scheme of an active roll reduction system using free-flooding tanks ... -
Effects of onshore and offshore environmental parameters on the leading edge erosion of wind turbine blades: A comparative study
Verma, Amrit Shankar; Jiang, Zhiyu; Ren, Zhengru; Hu, Weifei; Teuwen, Julie J.E. (Peer reviewed; Journal article, 2021)The presence of rain-induced leading edge erosion of wind turbine blades necessitates the development of erosion models. One of the essential parameters for erosion modelling is the relative impact velocity between rain ... -
Effects of Wind-Wave Misalignment on a Wind Turbine Blade Mating Process: Impact Velocities, Blade Root Damages and Structural Safety Assessment
Verma, Amrit Shankar; Jiang, Zhiyu; Ren, Zhengru; Gao, Zhen; Vedvik, Nils Petter (Peer reviewed; Journal article, 2020)Most wind turbine blades are assembled piece-by-piece onto the hub of a monopile-type offshore wind turbine using jack-up crane vessels. Despite the stable foundation of the lifting cranes, the mating process exhibits ...