检索结果-南通市图书馆

maglev self-excited vibration suppression with a virtual sky-hooked damper

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Central South University 2016年第6期23卷 1363-1371页

作者：李金辉李杰周丹峰王连春 College of Mechatronics Engineering and Automation National University of Defense Technology Changsha 410073 China Science and Technology on Near-surface Detection Laboratory Wuxi 214035 China

This work addresses the problem of self-excited vibration,which degrades the stability of the levitation control,decreases the ride comfort,and restricts the construction cost of maglev ***,a minimum model containing a flexible bridge and a single levitation unit is *** on the simplified model,the principle underlying the self-excited vibration is *** investigations about the energy transmission between the levitation system and bridge,it is concluded that the increment of modal damping can dissipate the accumulated energy by the bridge and the self-excited vibration may be *** enlarge the equivalent modal damping of bridge,the sky-hooked damper is ***,to avoid the hardware addition of real sky-hooked damper,considering the fact that the electromagnet itself is an excellent actuator that is capable of providing sufficiently fast and large force acting on the bridge to emulate the influence of the real sky-hooked damper,the technique of the virtual sky-hooked damper is *** principle underlying the virtual sky-hooked damper by electromagnet is explored and the vertical velocity of bridge is ***,numerical and experimental results illustrating the stability improvement of the vehicle-bridge interaction system are provided.

关键词： maglev vehicle-bridge interaction system self-excited vibration sky-hooked damper

Saturation influence of control voltage on maglev stationary self-excited vibration

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2016年第8期23卷 1954-1960页

作者：李金辉李杰余佩倡 College of Mechatronics Engineering and Automation National University of Defense Technology Changsha 410073 China The First Engineers Scientific Research Institute of the General Armaments Department Wuxi 214035 China

This work addresses the saturation influence of control voltage on the occurring of self-excited vibration of maglev vehicle-bridge interaction system, which greatly degrades the stability of the levitation control, decreases the ride comfort, and restricts the cost of the whole system. Firstly, the interaction model of vehicle-bridge system is developed. Based on the interaction model, the relationship between the control voltage and vibration frequency is solved. Then, the variation of the effective direct component and fundamental harmonic are discussed. Furthermore, from the perspective of energy transmission between the levitation system and bridge, the principle underlying the self-excited vibration is explored, and the influence on the stability is discussed. Finally, in terms of the variation of the characteristic roots, the influence is analyzed further and some conclusions are obtained. This study provides a theoretical guidance for mastering the self-excited vibration problems.

关键词： maglev levitation saturation self-excited vibration

A practical robust nonlinear controller for maglev levitation system

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2013年第11期20卷 2991-3001页

作者：李金辉李杰张耿 College of Mechatronics and Automation National University of Defense Technology

In order to explore the precise dynamic response of the maglev train and verify the validity of proposed controller,a maglev guideway-electromagnet-air spring-cabin coupled model is developed in the first *** on the coupled model,the stresses of the modules are analyzed,and it is pointed out that the inherent nonlinearity,the inner coupling,misalignments between the sensors and actuators,and external disturbances are the main issues that should be considered for the maglev ***,a feedback linearization controller based on the mathematical model of a maglev module is derived,in which the nonlinearity,coupling and misalignments are taken into ***,to attenuate the effect of external disturbances,a disturbance observer is proposed and the dynamics of the estimation error is analyzed using the input-to-state stability *** shows that the error is negligible under a low-frequency ***,at the high-frequency range,the error is unacceptable and the disturbances can not be compensated in time,which lead to over designed fluctuations of levitation gap,even a clash between the upper surface of electromagnet and lower surface of *** solve this problem,a novel nonlinear acceleration feedback is put forward to enhancing the attenuation ability of fast varying ***,numerical comparisons show that the proposed controller outperforms the traditional feedback linearization controller and maintains good robustness under disturbances.

关键词： dynamic robust nonlinear decoupling separation levitation system maglev

Design and analysis of superconducting magnets of a new mixed maglev model

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2005年第7期6卷 716-721页

作者：方攸同高重阳姚缨英 School of Electrical Engineering Zhejiang University School of Mechanical and Energy Engineering Zhejiang University

A new electromagnetic suspension model using a combination of high temperature superconductors (HTS) and copper conductors is proposed in this paper. A feasibility study showed that the magnets of our model can generate the 250 kg vertical suspension force. Three dimensional FEM and Design Sensitivity Analysis using the levitation gap length and cross sectional dimensions of the HTS magnets as design parameters were conducted to obtain the optimal shape of the cross section and the configuration of the HTS magnet. It was found that the gap length when optimized HTS magnet was used was much larger than that when copper conductor magnet was used, while the HTS coil volume was minimum, and the perpendicular field along the outer surface of the HTS coil was less than 0.12 T.

关键词： HTS maglev Magnet FEM

Observed response of maglev structure undercrossed by three shield tunnels in soft soil

在线全文

学校读者我要写书评

暂无评论

Underground Space 2022年第4期7卷 636-661页

作者： Dong-Mei Zhang Xiao-Chuang Xie Zhong-Kai Huang Mao-Zhu Peng Hong-Xin Zhu Key Laboratory of Geotechnical and Underground Engineering Ministry of EducationTongji UniversityShanghai 200092China Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China Centre for Offshore Foundation Systems University of Western Australia35 Stirling HighwayCrawleyPerthWA 6009Australia Shanghai Municipal Engineering Design Institute(Group)Co. Ltd.China

This paper investigates the response of a maglev structure to three under-crossing tunnels of the Shanghai Metro Line *** minimal distance between the tunnels and pile groups of the maglev structure is only 1.5 m,thus the deformations of the maglev structure are strictly controlled for the serviceability of the operating maglev *** displacements of maglev piers and ground settlements during different tunnelling stages are monitored with an automatic measuring *** on the observed data,the ground settlement trough and displacements of maglev piers caused by the three shield tunnelling procedures are analyzed and *** maximal ground settlement after the completion of the three tunnelling procedures is -43 *** operate the existing maglev safely,practical construction control methods are applied,including synchronous grouting,adjustment of the shield status,shield-advancing speed control,and stabilisation of the soil chamber *** these countermeasures,the tunnel-induced deformations of maglev piers are well below the predefined *** piers heave under the strict deformation criterion of 2.0 *** crossing project is finally completed without interruptions of the maglev operations by monitoring the *** presented project is a valuable example for the evaluation of shield tunnelling effects on the adjacent maglev structures and establishes criteria for similar projects in the future.

关键词： maglev Multi-crossing Shield tunnelling Ground settlement Pier displacement

Change monitoring of earth rotation parameter with maglev gyroscope precessional torque

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2011年第S3期21卷 589-593页

作者： YANG Zhi-qiang, GONG Yun, SHI Zhen, LI Yun Geological Engineering and Geomatics Institute, Chang’an University, Xi’an 710054, China Geological Engineering and Geomatics Institute Chang'an University Xi'an 710054 China

Through analyzing the relationship between gyro dynamic torques produced by the changes of earth rotation parameters (ERP), a method of measuring the earth rotation parameters was proposed and explored by using gyroscope. The preliminary experiments were carried out using GAT maglev Gyro Station (which is self-developed by China). Considering the measurement and expanding-application of the earth rotation parameters, some ideas and opinions about the structure design, measurement methods and data processing of gyro were proposed, and some outlook of the expanding-application of the gyroscope in geodetic and geophysical fields were done. The experimental results show that using the high-precision gyroscope to determine the changes of ERP is feasible, with the emergence of ultra-high precision gyro; it is possible for determining the earth rotation parameters by gyro in stead of by current complex space surveying technology.

关键词： maglev gyroscope earth rotation parameters (ERP) precessional torque pole motion length of day

Carrying capacity for the electromagnetic suspension low-speed maglev train on the horizontal curve

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2010年第4期53卷 1082-1087页

作者： CUI Peng,LI Jie & LIU DeSheng maglev Engineering Center,National University of Defense Technology,Changsha 410073,China maglev Engineering Center National University of Defense Technology Changsha China

Aiming at the lateral dislocation between the electromagnets and the rails on a horizontal curve,we investigated a single magnetic bogie of the maglev train in this *** magnetic levitation and guidance forces supplied by the suspension modules were deduced by the flux tube *** to the dynamic equilibrium equations of the maglev train on the curved track with cant,several major factors that influence the carrying capacity were analyzed,and the formula of the carrying capacity was *** results provide a theoretical reference for the design of maglev train.

关键词： low-speed maglev train curve flux tube carrying capacity

H infinity Control for Sandwiched maglev Stage with Dynamic Damping

在线全文

学校读者我要写书评

暂无评论

Journal of Beijing Institute of Technology 2019年第2期28卷 218-225页

作者： Ningran Song Shuyuan Ma Zongqing Zhang Shansi Zhang Changmeng Liu School of Mechanical Engineering Beijing Institute of Technology

An H infinity(H∞)controller for a sandwiched maglev positioning stage is *** maglev positioning stage has a special structure:a sandwiched maglev stage,consisting of repulsive linear motors and attractive linear motors,which have better levitation *** on the sandwiched maglev stage are analyzed and *** positioning controller is designed based on the feedback linearized model with a dynamic damping *** design of the H infinity controller for stage positioning is derived as a series of linear matrix inequalities(LMIs)which are efficiently solved in *** proposed controller and its effectiveness is demonstrated compared to PID method.

关键词： sandwiched structure positioning stage maglev technology H infinity(H∞)control

Magnetic Flux Density Modeling Method of maglev System 36

在线全文

学校读者我要写书评

暂无评论

Magnetic Flux Density Modeling Method of Maglev System