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, d...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.展开更多
This paper discusses the design of the propulsion system of the UAQ4 （University of L＇Aquila, model 4） magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only...This paper discusses the design of the propulsion system of the UAQ4 （University of L＇Aquila, model 4） magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only magnetic levitating vehicle with resistance motion, except for aerodynamic drag and with energy consumption near zero at low speed. The feasibility of the system has been successfully verified and tested in the laboratory. Propulsion and braking are provided by a novel direct-current linear stepper motor, with the primary formed by permanent magnets distributed on central beam of the track, and the secondary by coils on board the vehicle, instead of the present alternate current linear motors that have well-known disadvantages. The motor working principles are described, and its performances are analyzed, by a finite element numerical model which allows modifying the most important parameters of the system. The main components of a full scale motor for urban transportation are measured and discussed.展开更多
The theory of dynamic vibration absorber(DVA)was applied to restrain the vibration of carbody for high-speed electric multiple unit(EMU).The carbody was modeled as an Euler-Bernoulli beam with the equipment mounted on...The theory of dynamic vibration absorber(DVA)was applied to restrain the vibration of carbody for high-speed electric multiple unit(EMU).The carbody was modeled as an Euler-Bernoulli beam with the equipment mounted on the chassis regarded as a DVA.Suspension parameters of the equipment were optimized based on the modal analysis of the beam and parameter optimization of the DVA.Vertical motion equations of the carbody and equipment were derived to study the effect of the suspension parameters on the vibration of carbody,which included the suspension frequency,damping ratio,mounting position and mass.Then a 3D rigid-flexible coupled vehicle system dynamics model was built to simulate the response of carbody and equipment to track excitation.The results show that the equipment mounted on the carbody chassis can be regarded as a DVA to reduce the flexible vibration of carbody,and the optimum suspension frequency can be calculated theoretically with the first-order vertical bending mode of carbody considered.Heavy equipment should be mounted to the carbody center as close as possible to obtain a significant vibration reduction,while light equipment has quite limited contribution to that.Also,a laboratory test was conducted on the full-scale test rig which shows a good agreement with the theoretical analysis and dynamic simulations.The faster the vehicle runs,the more significant are the advantages of the elastic suspension.展开更多
基金Projects(11302252,11202230)supported by the National Natural Science Foundation of China
文摘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.
文摘This paper discusses the design of the propulsion system of the UAQ4 （University of L＇Aquila, model 4） magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only magnetic levitating vehicle with resistance motion, except for aerodynamic drag and with energy consumption near zero at low speed. The feasibility of the system has been successfully verified and tested in the laboratory. Propulsion and braking are provided by a novel direct-current linear stepper motor, with the primary formed by permanent magnets distributed on central beam of the track, and the secondary by coils on board the vehicle, instead of the present alternate current linear motors that have well-known disadvantages. The motor working principles are described, and its performances are analyzed, by a finite element numerical model which allows modifying the most important parameters of the system. The main components of a full scale motor for urban transportation are measured and discussed.
基金supported by the National Science and Technology Support Program of China(2009BAG12A01-A02)the New Century Excellent Talents of Ministry of Education funded project(NCET-10-0664)+2 种基金the National Natural Science Foundation of China(Grant No.61134002)the National Basic Research Program of China("973"Program)(Grant No.2011CB711106)China Postdoctoral Science Foundation funded project(No:2014M550471)
文摘The theory of dynamic vibration absorber(DVA)was applied to restrain the vibration of carbody for high-speed electric multiple unit(EMU).The carbody was modeled as an Euler-Bernoulli beam with the equipment mounted on the chassis regarded as a DVA.Suspension parameters of the equipment were optimized based on the modal analysis of the beam and parameter optimization of the DVA.Vertical motion equations of the carbody and equipment were derived to study the effect of the suspension parameters on the vibration of carbody,which included the suspension frequency,damping ratio,mounting position and mass.Then a 3D rigid-flexible coupled vehicle system dynamics model was built to simulate the response of carbody and equipment to track excitation.The results show that the equipment mounted on the carbody chassis can be regarded as a DVA to reduce the flexible vibration of carbody,and the optimum suspension frequency can be calculated theoretically with the first-order vertical bending mode of carbody considered.Heavy equipment should be mounted to the carbody center as close as possible to obtain a significant vibration reduction,while light equipment has quite limited contribution to that.Also,a laboratory test was conducted on the full-scale test rig which shows a good agreement with the theoretical analysis and dynamic simulations.The faster the vehicle runs,the more significant are the advantages of the elastic suspension.
