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Xie Y.-D.,Beijing Enterprises Holding Maglev Technology Development Co. | Xie Y.-D.,National University of Defense Technology | Li Y.-G.,National University of Defense Technology | Long Z.-Q.,National University of Defense Technology | Dai C.-H.,National University of Defense Technology
Zidonghua Xuebao/Acta Automatica Sinica | Year: 2014

The boundary characteristic curves of linear regions with the second-order discrete time optimal control are presented using the method of the state back step. The control variable is decided by the linearized criterion according to the relative position between phase plane point and switching curve, and the boundary characteristic curves. The reachable region and the boundary region are given. Then some sectionalized constructed linear synthetic functions are obtained. Based on this function, the discrete form of tracking-differentiator (TD) is constructed. This algorithm is able to amend its characteristic points and is flexible to applications. It does not contain the square roots algorithm, and its form is simple and its implement action is easy. Numerical simulation of sinusoidal wave and square wave shows that this discrete form of tracking-differentiator can quickly track an input signal without overshooting or chattering and can produce a good differential signal. Its effect is similar to one of the nonlinear boundary transformation. A kind of TD group with phase compensation and filter ability is acquired using the moving average algorithm. The excellent filter ability and phase compensation are obtained after a proper TD parameter choice. The velocity and position detection of a permanent magnet electro dynamic maglev train system based on long stator alveolus count employs the above scheme. The running experiment of the train shows that the above algorithm can effectively remove noise and lead to little phase delay, and amend distortion signals at the guide juncture. The algorithm is easy, effective and convenient to engineering implementation action. Copyright © 2014 Acta Automatica Sinica. All rights reserved. Source


Liu Y.,National University of Defense Technology | Deng W.,Beijing Enterprises Holding Maglev Technology Development Co. | Gong P.,Beijing Enterprises Holding Maglev Technology Development Co.
Shock and Vibration | Year: 2015

A dynamic model of the bogie of maglev train with distributed magnetic forces and four identical levitating controllers is formulated. The vertical, pitching, and rolling degree of freedom of the electromagnet modules and their coupling are considered. The frequency responses of the bogie to track irregularity are investigated with numerical simulation. The results tell us that there are resonances related to the first electromagnetic suspension whose frequencies are determined by the control parameters. A comparative analysis has been carried out between the models with distributed or concentrated magnetic forces. The comparison indicates that simplifying the distributed magnetic force to concentrated one degenerates the dynamic behavior of the maglev bogie, especially resulting in overestimated resonances of the first electromagnetic suspension of maglev trains. The results also indicate that those resonances only occur on specific wavelengths of irregularity that relate to the length of the electromagnets. © 2015 Yaozong Liu et al. Source


Liu Y.-Z.,National University of Defense Technology | Deng W.-X.,National University of Defense Technology | Deng W.-X.,Beijing Enterprises Holding Maglev Technology Development Co. | Li J.,National University of Defense Technology | And 2 more authors.
Tiedao Xuebao/Journal of the China Railway Society | Year: 2014

Anti-rolling and decoupling are the two important functions of low-speed maglev bogies. Utilizing the virtual prototyping technology, the different characteristics of the elastic-decoupling mode and the geometric-decoupling mode of the boom-type anti-rolling and decoupling mechanism (ADM) were investigated. Restraints between anti-rolling and decoupling were presented. The geometry-decoupling mechanism demonstrated asymmetric features, i.e., the rolling angles between the left and right suspension modules and tracks that met were different, which put a maglev train at a disadvantage in view of running safety. Since track irregularities and gap fluctuations of levitation were unavoidable, the semi-elastic decoupling mode was recommended for the boom-type ADM. Source


Xie Y.-D.,Beijing Enterprises Holding Maglev Technology Development Co. | Xie Y.-D.,National University of Defense Technology | Li X.-L.,National University of Defense Technology | She L.-H.,Beijing Enterprises Holding Maglev Technology Development Co. | And 3 more authors.
Kongzhi yu Juece/Control and Decision | Year: 2014

The boundary characteristic curve of linear regions with the second-order discrete time optimal control is presented by means of the isochronous region. Then the control variable is linearized, which is decided by the switching curve and the boundary curve, and the reachable region and the boundary region are given. The linear synthetic functions are obtained. Based on this function, the discrete form of tracking-differentiator is constructed. Numerical simulation shows that, this discrete form of tracking-differentiator can quickly track an input signal without overshooting and chattering, and can acquire an excellent differential signal. It is simple and practical. Source

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