H∞ Vibration Control of Active Suspension for High-Speed Train

1995 ◽  
Vol 7 (4) ◽  
pp. 319-323
Author(s):  
Akihiko Shimura ◽  
◽  
Kazuo Yoshida

In this paper, H∞ control theory and <I>μ</I> synthesis are applied to vibration control of active suspension for high speed train. A linear 58th order model is built for the dynamical analysis of the train model. This model takes into account the body, truck frame, wheel, hydraulic actuator, and property of track irregularity. A hydraulic actuator replaces a lateral damper between body and truck frame of the conventional passive suspension train. The controller for vibration control is synthesized by H∞ control synthesis and improved by <I>μ</I> synthesis. The characteristics and performances of the controllers are examined by performing numerical calculations of frequency response and computational simulations. As a result, it is clarified that the active suspension for highspeed train is effective to improve ride quality and that the present synthesis method is useful.

Author(s):  
Ali Al-Zughaibi ◽  
Yiqin Xue ◽  
Roger Grosvenor ◽  
Aniekan Okon

Fully active electrohydraulic control of a quarter-car test rig is considered from both a modelling and experimental point of view. This paper develops a nonlinear active hydraulic design for the active suspension system, which improves the inherent trade-off between ride quality and suspension travel. The novelty is in the use of pole assessment controller to drive a nonlinear active suspension with a new insight into the model through consideration of a new term, friction forces. Therefore, this model has taken into account the dynamic inclination angle [Formula: see text] between linkage and actuator regardless of the fact that the designer made an only vertical motion (bounce mode) of the wheel and body units. The second contribution of this paper is that it investigated the control force generation, therefore, the nonlinear hydraulic actuator whose effective bandwidth depends on the magnitude of the suspension travel, which incorporates the dynamic equation of servovalve, is deeply researched. The nonlinear friction model is accurately established, which relies on the dynamics system analysis and the fact of slipping the body on lubricant supported bearings; this model will caption all the friction behaviours that have been observed experimentally. In addition, the hydraulic system is used to generate the system inputs as a road simulator. The controller smoothly shifts its focus between the conflicting objectives of ride comfort and rattle space utilisation, softening the suspension when suspension travel is small and stiffening it as it approaches the travel limits. Thus, the nonlinear design allows the closed-loop system to behave differently in different operating regions. The improvement achieved with our design is illustrated through comparative experiments and simulations. C++ compiler environment is used to simulate the physical system to be controlled. The results show good servo control and fast regulation of abrupt disturbances.


Author(s):  
YK Wu ◽  
JL Mo ◽  
B Tang ◽  
JW Xu ◽  
B Huang ◽  
...  

In this research, the tribological and dynamical characteristics of a brake pad with multiple blocks are investigated using experimental and numerical methods. A dynamometer with a multiblock brake pad configuration on a brake disc is developed and a series of drag-type tests are conducted to study the brake squeal and wear behavior of a high-speed train brake system. Finite element analysis is performed to derive physical explanations for the observed experimental phenomena. The experimental and numerical results show that the rotational speed and braking force have important influences on the brake squeal; the trends of the multiblock and single-block systems are different. In the multiblock brake pad, the different blocks exhibit significantly different magnitudes of contact stresses and vibration accelerations. The blocks located in the inner and outer rings have higher vibration acceleration amplitudes and stronger vibration energies than the blocks located in the middle ring.


2010 ◽  
Vol 29-32 ◽  
pp. 835-840 ◽  
Author(s):  
Zhi Peng Feng ◽  
Ji Ye Zhang ◽  
Wei Hua Zhang

As the speed of train increases, flow-induced vibration of trains passing through tunnels has become a subject of discussion, to investigate this phenomenon, a simplified geometric model and a vehicle dynamics model of a high-speed train traveling through a tunnel were built. To analyze the unsteady three-dimensional flow around the train, the 3-D, transient, viscous, compressible Reynolds-averaged Navier-Stokes equations combined with the k- two-equation turbulence model were solved with the finite volume method. The motion of the train was carried out using the technique of sliding grid method. The dynamics response of the train was obtained by means of the computational multi-body dynamics calculation. Meanwhile the running safety and riding comfort of the train were analyzed. With the numerical simulation, the variation of aerodynamic forces was obtained. The research founds that, vibration of the train increases drastically during it passing through a tunnel. The running safety and riding quality of the train are reduced greatly but they are in the safe range.


2021 ◽  
Author(s):  
Yu SUN ◽  
Jinsong Zhou ◽  
Dao Gong ◽  
Yuanjin Ji

Abstract To absorb the vibration of the carbody of the high-speed train in multiple degrees of freedom, a multi-degree of freedom dynamic vibration absorber (MDOF DVA) is proposed. Installed under the carbody, the natural vibration frequency of the MDOF DVA from each DOF can be designed as a DVA for each single degree of freedom of the carbody. Hence, a 12-DOF model including the main vibration system and a MDOF DVA is established, and the principle of Multi-DOF dynamic vibration absorption is analyzed by combining the design method of single DVA and genetic algorithm. Based on a high-speed train dynamics model including an under-carbody MDOF DVA, the vibration control effect on each DOF of the MDOF DVA is analyzed by the virtual excitation method. Moreover, a high static and low dynamic stiffness (HSLDS) mount is proposed based on a cam–roller–spring mechanism for the installation of the MDOF DVA due to the requirement of the low vertical dynamic stiffness. From the dynamic simulation of a non-linear model in time-domain, the vibration control performance of the MDOF DVA installed with nonlinear HSLDS mount on the carbody is analyzed. The results show that the MDOF DVA can absorb the vibration of the carbody in multiple degrees of freedom effectively, and improve the running ride quality of the vehicle.


Author(s):  
Qinlin Cai ◽  
Yingyu Hua ◽  
Songye Zhu

Electromagnetic damper cum energy harvester (EMDEH) is an emerging dual-function device that enables simultaneous energy harvesting and vibration control. This study presents a novel energy-harvesting adaptive vibration control application of EMDEH on the basis of the past EMDEH development in passive control. The proposed EMDEH comprises an electromagnetic damper connected to a specifically designed energy harvesting circuit (EHC), wherein the EHC is a buck–boost converter with a microcontroller unit (MCU) and a bridge rectifier. The effectiveness of the energy-harvesting adaptive vibration damping is validated numerically through a high-speed train (HST) model running at different speeds. MCU-controlled adaptive duty cycle adjustment in the EHC enables the EMDEHs to adaptively offer the optimal damping coefficients that are highly dependent on train speeds. In the meantime, the harvested power can be stored in rechargeable batteries by the EHC. Numerical results project the average output power ranging from 40.5[Formula: see text]W to 589.8[Formula: see text]W from four EMDEHs at train speed of 100–340[Formula: see text]km/h, with a maximum output power efficiency of approximately 35%. In comparison to energy-harvesting passive vibration control and a pure viscous damper, the proposed energy-harvesting adaptive control strategy can improve vibration reductions by approximately 40% and 27%, respectively, at a speed of 340[Formula: see text]km/h. These numerical results clearly demonstrate the benefit and prospect of the proposed energy-harvesting adaptive vibration control in HST suspensions.


Author(s):  
Vahid Bokaeian ◽  
Mohammad A Rezvani ◽  
Robert Arcos

This study is focused on the effects of bending and torsional flexural modes of the car body on the ride quality index of a high-speed train vehicle. The Euler–Bernoulli beam model is used to extract an analytical model for a high-speed train vehicle car body in order to investigate its bending and torsional flexural vibrations. The rigid model includes a car body, two bogie frames, and four wheelsets such that, each mass has three degrees of freedom including vertical displacement, pitch motion, and roll motion. The results obtained with the proposed analytical model are compared with experimental measurements of the car body response of a Shinkansen high-speed train. Moreover, it is determined that the bending and torsional flexural modes have significant effects on the vertical acceleration of the car body, particularly in the 9–15 Hz frequency range. Furthermore, the ride quality index is calculated according to the EN 12299 standard and it is shown that the faster the train the more affected is the ride quality by the flexural modes. In addition, the effect of coherence between two rail irregularities (the right and the left rails) on the results of the simulation is investigated. The results conclude that if the irregularities are completely correlated the torsional flexural mode of the car body does not appear in the response. Also, the first bending flexural mode in such cases is more excited compared with the partially correlated or uncorrelated rail irregularities. Therefore, the ride quality index in completely correlated cases is higher than other cases.


Author(s):  
P.E. Orukpe

In this paper, we apply model predictive control (MPC) based on mixed H2/H to active vibration control of the flexibility of railway vehicle to improve ride quality. However, the flexibility in the body of high-speed railway vehicles creates difficulties which in practice may result in the body structure being heavier than what it is supposed to be. The use of active suspension helps to model the vehicle and its flexibility in an effective manner. Conventional control approaches are compared with linear matrix inequality MPC technique using flexible-bodied railway vehicle as an example. The result indicates that the MPC technique performs better in improving ride comfort compared to the passive and classical techniques when flexible modes are present.


1970 ◽  
Vol 185 (1) ◽  
pp. 553-563 ◽  
Author(s):  
A. G. Thompson

The synthesis method is employed for the design of servo-suspensions of the electro-hydraulic type. Two alternative arrangements are considered in which the hydraulic actuators and the body support springs are respectively in series and in parallel. The achieved designs for active suspensions of this type are superior to conventional systems both in ride quality and in overall stiffness to resist body load forces, but slightly less effective in regard to road-holding. If dynamic absorbers are used for the control of axle vibrations it is shown that considerably greater improvements in ride quality than hitherto possible may be obtained with the aid of an additional feedforward compensating signal flow path. The derivation of the necessary compensation circuits to achieve the specified overall system performances is demonstrated by examples. A simple method of banking control of the vehicle by inclined sensing accelerometers is suggested.


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