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H∞position transfer and regulation for floating offshore wind turbines

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Control Theory and Technology 2020年第3期18卷 231-245页

作者： Eduardo Eribert ESCOBAR AQUINO ryozo nagamune Department of Mechanical Engineering The University of British ColumbiaVancouverBC V671Z4Canada

This paper proposes H∞controller design for platform position transfer and regulation of floating offshore wind *** platform movability of floating wind turbines can be utilized in mitigating the wake effect in the wind farm,thereby maximizing the wind farm's total power capture and *** controller is designed so that aerodynamic force is adjusted to meet the three objectives simultaneously,that is,1)to generate the desired electrical power level,2)to achieve the desired platform position,and 3)to suppress the platform *** acquire sufficient aerodynamic force to move the heavy platform,the pitch-to-stall blade pitching strategy is taken instead of the commonly-used pitch-to-feather *** desired power level is attained by the standard constant-power strategy for the generator torque,while Hstate-feedback control of blade pitch and nacelle yaw angles is adopted for the position regulation and platform oscillation *** constants for the H∞controller design are adjusted to take the trade-off between the position regulation accuracy and the platform motion *** demonstrate the efficiency of the proposed controler,a virtual 5-MW semi-submersible wind turbine is *** results show that the designed H∞controller successfully accomplishes the platform position transfer and regulation as well as the platform oscillation reduction against wind and wave disturbances,and that it outperforms a previously-proposed linear quadratic controller with an integrator.

关键词： Offshore wind farm wind turbine position power regulation disturbance rejection H∞control

Double-loop robust tracking control for micro machine tools

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Science China(Technological Sciences) 2011年第11期54卷 3054-3063页

作者： FAN ShiXun nagamune ryozo FAN DaPeng College of Mechatronic Engineering and Automation National University of Defense Technology Changsha 410073 China Department of Mechanical Engineering the University of British Columbia Vancouver BC V6TIZ4 Canada

This paper addresses double-loop robust tracking controller design of the miniaturized linear motor drive precision stage with mass and damping ratio uncertainties. As an inner-loop, a disturbance observer （DOB） is employed to suppress exogenous low frequency disturbances such as friction and cutting force. To further eliminate the residual disturbance and to guarantee the robust tracking to the reference input, μ-synthesis outer-loop controller is designed. For eliminating the steady state error, a technique is proposed to design the μ-synthesis outer-loop controller with an integrator. A guideline to select the bandwidth of the Q-filter in the DOB is provided. Simulations using a model of a prototype micro-milling machine indicate that the proposed outer-loop synthesis scheme is superior to the H∞ suboptimal control in disturbance rejection performance and steady state tracking performance. Furthermore, it is shown experimentally that the proposed double-loop robust tracking controller improves the tracking performance of the stage by 29.6% over PID control with a DOB inner-loop.

关键词： micro machine tools robust tracking μ-synthesis disturbance observer

Platform motion minimization using model predictive control of a floating offshore wind turbine

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Theoretical & Applied Mechanics Letters 2021年第5期11卷 291-295页

作者： Kamran Ali Shah Ye Li ryozo nagamune Yarong Zhou Waheed Ur Rehman Multi-function Towing Tank Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Ocean Engineering School of Naval ArchitectureOcean&Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Mechanical Engineering The University of British ColumbiaVancouverBCV6T1Z4 Canada Swedish College of Engineering and Technology Rahim Yar Khan Pakistan

Wind turbines are installed offshore with the assistance of a floating platform to help meet the world’s increasing energy ***,the incident wind and extra incident wave disturbances have an impact on the performance and operation of the floating offshore wind turbine(FOWT)in comparison to bottom-fixed wind *** this paper,model predictive control(MPC)is utilized to overcome the limitation caused by platform *** to the ease of control synthesis,the MPC is developed using a simplified model instead of high fidelity simulation *** performance of the controller is verified in the presence of realistic wind and wave *** study demonstrates the effectiveness of MPC in reducing platform motions and rotor/generator speed regulation of FOWTs.

关键词： Wind energy Floating offshore wind turbine Platform motion Model predictive control

Floating Wind Turbine Motion Suppression Using an Active Wave Energy Converter

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Instrumentation 2019年第1期6卷 85-97页

作者： Anderson R.W.SOARES ryozo nagamune Department of Mechanical Engineering The University of British Columbia VancouverBC V6T 1Z4Canada

This paper proposes a new concept of an actively-controlled wave energy converter for suppressing the pitch and roll motions of floating offshore wind *** wave energy converter consists of several floating bodies that receive the wave energy,actuators that convert the wave energy into electrical energy and generate the mechanical forces,and rigid bars that connect the floating bodies and the wind turbine platform and deliver the actuator forces to the *** rotational torques that are required to minimize the platform pitch and roll motions are determined using a linear quadratic *** torques determined in this manner are realized through the actuator forces that maximize the wave power capture as *** performance of the proposed wave energy converter in simultaneously suppressing the platform pitch and roll motions and extracting the wave energy is validated through simulations.

关键词： Floating Wind Turbine Wave Energy Converter Platform Motion Suppression Linear Quadratic Regulator Power Capture Maximization

Simultaneous measurements of aeroacoustic sounds and wall vibration for exploring the contribution of tooth vibration in the production of sibilant sounds/s/

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Journal of Biomedical Science and Engineering 2011年第2期4卷 83-89页

作者： Masanori Nakamura Kazunori Nozaki Haruka Takimoto Kazuya nagamune Motoharu Fujigaki Shigeo Wada 不详

In order to understand the contribution of teeth vibration to the production of sibilant/s/, the pre-sent study was designed to develop a method of simultaneously measuring aeroacoustic sounds and the vibration of an obstacle. To measure the vibration without disturbing flow, the Michelson interferometer was employed. The flow channel, which had an obstacle wall inside of it, was fabricated such that it morphologically mimicked the simplified geometry of the oral cavity. Given airflows at a flow rate of 7.5 × 10–4 m3/s from the inlet, aeroacoustic sounds were generated. A spectrum analy-sis of the data demonstrated two prominent peaks in the sound at 1,300 and 3,500 Hz and one peak in the wall vibration at 3,500 Hz. The correlation in peak frequencies between the sound and wall vibration suggests that the sound at 3,500 Hz was induced by the wall vibration. In fact, the sound amplitude at 3,500 Hz decreased when the obstacle wall was thickened, which increased its rigidity (p < 0.05, t-test). The experimental results demonstrate that the developed techniques are capable of measuring aeroacoustic sound and obstacle wall vibration simultaneously, and suggest the potential to pave the way for detailed analysis of the production of sibilant sounds /s/.

关键词： Acoustic Measurement Vibration Measurement Michelson Interferometer Aeroacoustics Sibilant/s/

A sensitive homogeneous non-competitive immunoassay using β-galactosidase complementation for the detection of small haptens

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A sensitive homogeneous non-competitive immunoassay using β...