Passive Multi-Degree-of-Freedom Stabilization of Ultra-High-Speed Maglev Vehicles

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Salvatore Circosta ◽  
Renato Galluzzi ◽  
Nicola Amati ◽  
Andrea Tonoli ◽  
Angelo Bonfitto ◽  
...  

Abstract Over the last decades, the search for fast and efficient transportation systems has raised the interest toward maglev technologies. In this scenario, the Hyperloop paradigm is regarded as a breakthrough for future mobility. However, its practical implementation requires the solution of key shortcomings. Among these, the stability of the electrodynamic levitation system remains partially unexplored. The state of the art presents numerous attempts to attain stable behavior. In recent works, the stabilization of maglev vehicles has been addressed only for the vertical dynamics. Nevertheless, stable operation of all degree-of-freedom is required for a successful implementation of these transportation systems. The present paper addresses the full stabilization of a downscaled vehicle where levitation and guidance are provided by electrodynamic means. To this end, a design methodology supported by analytical modeling is proposed, where the degree-of-freedom are stabilized by suitably introducing secondary suspension elements. The design of the secondary suspension and the guidance system is obtained through the optimization of stability and dynamic performance. Then, a multibody model is developed. Both numerical approaches are compared in the frequency domain for validation purposes. Finally, the multibody model is simulated in the time domain to assess system performance in the presence of track irregularities and evaluate coupling effects between the degree-of-freedom.

Transport ◽  
2007 ◽  
Vol 22 (3) ◽  
pp. 139-147 ◽  
Author(s):  
Rainer Schach ◽  
René Naumann

In this paper a substantial comparison of different high‐speed transportation systems and an approach to stochastic cost estimations are provided. Starting from the developments in Europe, the high‐speed traffic technical characteristics of high‐speed railways and Maglev systems are compared. But for a comprehensive comparison more criterions must be included and led to a wider consideration and the development of a multi‐criteria comparison of high‐speed transportation systems. In the second part a stochastic approach to cost estimations of infrastructure projects is encouraged. Its advantages in comparison with the traditional proceeding are presented and exemplify the practical implementation.


Author(s):  
Dan Baiasu ◽  
Gheorghe Ghita ◽  
Ioan Sebesan

The paper presents the opportunity of using a magneto-rheological damper to control the lateral oscillations of a passenger railway vehicle to increase its comfort and speed features. The lateral dynamics of the vehicle is simulated using a multibody model with 17 degrees of freedom considering the lateral, yawing and rolling oscillations. The equations describing the model are integrated by the authors using original software. The mathematical model considers the geometrical nonlinearities of the wheel-track contact. The nonlinear stability of the vehicle running on tangent tracks with irregularities is assessed and it is shown the influence of the construction parameters of the suspensions on the vehicle’s performance. A magneto-rheological device with sequential damping based on balance logic control strategy is introduced in the secondary suspension of the vehicle to reduce the lateral accelerations generated by the track’s irregularities. The system’s response in terms of accelerations is compared for both passive and semi-active cases. It is shown that the magneto-rheological semi-active suspension improves the safety and the comfort of the railway vehicle.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Jun Guan ◽  
Wenjun Yi

The article establishes a seven-degree-of-freedom projectile trajectory model for a new type of spinning projectile. Based on this model, a numerical analysis is performed on the ballistic characteristics of the projectile, and the trajectory of the dual-spinning projectile is filtered with the unscented Kalman filter algorithm, so that the measurement information of projectile onboard equipment is more accurate and more reliable measurement data are provided for the guidance system. The numerical simulation indicates that the dual-spinning projectile is mainly different from the traditional spinning projectile in that a degree of freedom is added in the direction of the axis of the projectile, the forebody of the projectile spins at a low speed or even holds still to improve the control precision of the projectile control system, while the afterbody spins at a high speed maintaining the gyroscopic stability of the projectile. The trajectory filtering performed according to the unscented Kalman filter algorithm can improve the accuracy of measurement data and eliminate the measurement error effectively, so as to obtain more accurate and reliable measurement data.


2013 ◽  
Vol 409-410 ◽  
pp. 1486-1491
Author(s):  
Zhuo Yu He

In the secondary suspension of urban rail vehicles and high-speed passenger trains, combination of air springs and anti-roll torsion bar is widely used. However, in its practical use, cracks appear in the anti-roll torsion bar and vehicle curve performance is lower. Through analysis of anti-roll torsion bar, acceleration being taken into account, the dynamics models of anti-roll torsion bar and the vehicle itself are established. The results indicate that the combination of anti-roll torsion bar and rubber joints is superior to present a more reasonable anti-roll stiffness, to ensure better dynamic performance of the train, and also to lengthen the life of the anti-roll torsion bar.


Author(s):  
Ren Luo ◽  
Changdong Liu ◽  
Huailong Shi

A secondary suspension configuration that integrates the Interconnected Hydro-Pneumatic Struts (IHPS) to the air spring system is proposed in this investigation for railway vehicles. Using the dynamic performance of IHPS, this suspension aims to provide smaller vertical supporting stiffness and larger anti-roll resistance compared to the traditional configuration, the air spring is connected to an emergency rubber spring in series with quite large stiffness. By replacing the rubber spring with IHPS, the proposed suspension configuration contributes to vibration absorption as well as anti-roll stiffness of the vehicle. The IHPS has two hydraulic cylinders installed in parallel to support the suspended mass. Each hydraulic cylinder has three oil chambers, and the oil chambers between the left and right struts are cross-connected through pipelines. Considering the oil compressibility and the vibration of liquid in the interconnected pipes, the mathematical model of IHPS is formulated and established in MATLAB. A multi-body dynamic railway vehicle model is built in SIMPACK, into which the IHPS is integrated through a co-simulation technique. Model validations on the IHPS are performed and its static and dynamic stiffness is examined. Numerical simulations show that the IHPS suspension reduces the vertical acceleration on the car body floor at a frequency between 1 and 3 Hz than the traditional air spring system with/without an anti-roll bar configuration. The vertical Sperling index of the vehicle using the IHPS suspension is smaller than that of the traditional suspensions, and it is more significant when the air spring deflates. However, the vertical acceleration with IHPS is larger than the traditional suspensions at 13∼55 Hz when the air spring deflates.


Author(s):  
E. E. Swanson ◽  
H. Heshmat

Gas turbine engines and other high speed rotating machinery supported by magnetic bearings require some form of backup bearing to ensure reliable and safe operation. To date, this backup capability has been provided by either rolling element bearings or solid lubricated bushings. Both of these solutions have drawbacks — must notably limited life and uncertain dynamic performance. In many cases, the backup bearing system requires substantial maintenance following an activation event. An alternative approach investigated in this work is the use of a compliant foil bearing as a backup bearing. This work discusses tests of this concept on a test rig with a 63 kg rotor. In this application, the foil bearing demonstrated smooth, stable operation during a variety of simulated magnetic bearing failure events, and allowed for continued operation of the rotor following the simulated failures.


Author(s):  
Qixin Zhu ◽  
Lei Xiong ◽  
Hongli Liu ◽  
Yonghong Zhu ◽  
Guoping Zhang

Background: The conventional method using one-degree-of-freedom (1DOF) controller for Permanent Magnet Synchronous Motor (PMSM) servo system has the trade-off problem between the dynamic performance and the robustness. Methods: In this paper, by using H∞ control theory, a novel robust two-degree-of-freedom (2DOF) controller has been proposed to improve the position control performance of PMSM servo system. Using robust control theory and 2DOF control theory, a H∞ robust position controller has been designed and discussed in detail. Results: The trade-off problem between the dynamic performance and robustness which exists in one-degree-of-freedom (1DOF) control can be dealt with by the application of 2DOF control theory. Then, through H∞ control theory, the design of robust position controller can be translated to H∞ robust standard design problem. Moreover, the control system with robust controller has been proved to be stable. Conclusion: Further simulation results demonstrate that compared with the conventional PID control, the designed control system has better robustness and attenuation to the disturbance of load impact.


2019 ◽  
Vol 12 (4) ◽  
pp. 339-349
Author(s):  
Junguo Wang ◽  
Daoping Gong ◽  
Rui Sun ◽  
Yongxiang Zhao

Background: With the rapid development of the high-speed railway, the dynamic performance such as running stability and safety of the high-speed train is increasingly important. This paper focuses on the dynamic performance of high-speed Electric Multiple Unit (EMU), especially the dynamic characteristics of the bogie frame and car body. Various patents have been discussed in this article. Objective: To develop the Multi-Body System (MBS) model of EMU, verify whether the dynamic performance meets the actual operation requirements, and provide some useful information for dynamics and structural design of the proposed EMU. Methods: According to the technical characteristics of a typical EMU, a MBS model is established via SIMPACK, and the measured data of China high-speed railway is taken as the excitation of track random irregularity. To test the dynamic performance of the EMU, including the stability and safety, some evaluation indexes such as wheel-axle lateral forces, wheel-axle lateral vertical forces, derailment coefficients and wheel unloading rates are also calculated and analyzed in detail. Results: The MBS model of EMU has better dynamic performance especially curving performance, and some evaluation indexes of the stability and safety have also reached China’s high-speed railway standards. Conclusion: The effectiveness of the proposed MBS model is verified, and the dynamic performance of the MBS model can meet the design requirements of high-speed EMU.


1997 ◽  
Vol 33 (3) ◽  
pp. 214
Author(s):  
R. LaComb ◽  
D.K. Wagner ◽  
L. DiMarco ◽  
J. Connolly

Cryogenics ◽  
2021 ◽  
pp. 103321
Author(s):  
Yuhang Yuan ◽  
Jipeng Li ◽  
Zigang Deng ◽  
Zhehao Liu ◽  
Dingding Wu ◽  
...  

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