Validation of Railway Vehicle System Models

1984 ◽  
pp. 387-400 ◽  
Author(s):  
Vijay K. Garg ◽  
Rao V. Dukkipati
Keyword(s):  
Railway Vehicle ◽  
System Models ◽  
Vehicle System

Development of a reduced dynamic model for comfort evaluation of rail vehicle systems

2016 ◽  
Vol 230 (4) ◽  
pp. 489-504 ◽  
Author(s):  
Mortadha Graa ◽  
Mohamed Nejlaoui ◽  
Ajmi Houidi ◽  
Zouhaier Affi ◽  
Lotfi Romdhane
Keyword(s):  
Dynamic Model ◽  
Degrees Of Freedom ◽  
Dynamic Models ◽  
Railway Vehicle ◽  
Passenger Comfort ◽  
Rail Vehicle ◽  
Vehicle System ◽  
Comfort Evaluation ◽  
Complex Models ◽  
Reduced Dynamic

In this paper, an analytical reduced dynamic model of a rail vehicle system is developed. This model considers only 38 degrees of freedom of the rail vehicle system. This reduced model can predict the dynamic behaviour of the rail vehicle while being simpler than existing dynamic models. The developed model is validated using experimental results found in the bibliography and its results are compared with existing more complex models from the literature. The developed model is used for the passenger comfort evaluation, which is based on the value of the weighted root mean square acceleration according to the ISO 2631 standard. Several parameters of the system, i.e., passenger position, loading of the railway vehicle and its speed, and their effect on the passenger comfort are investigated. It was shown that the level of comfort is mostly affected by the speed of the railway vehicle and the position of the seat. The load, however, did not have a significant effect on the level of comfort of the passenger.

Mechatronic suspension design for full rail vehicle system

2016 ◽  
Vol 231 (4) ◽  
pp. 571-590 ◽  
Author(s):  
Mortadha Graa ◽  
Mohamed Nejlaoui ◽  
Ajmi Houidi ◽  
Zouhaier Affi ◽  
Lotfi Romdhane
Keyword(s):  
Tracking Error ◽  
Linear Quadratic Regulator ◽  
Experimental Result ◽  
Railway Vehicle ◽  
Linear Quadratic ◽  
Rail Vehicle ◽  
Vehicle System ◽  
Frequency Domains ◽  
Rail Irregularities ◽  
Vehicle Motion

In this paper, an analytical mechatronic dynamic design model of a full rail vehicle system is developed. Based on the rail vehicle motion, its degree of freedom can be reduced to only 38. This reduction is necessary for the model simplicity. The developed model is validated with experimental result and compared with other one from literature. The real characteristics of the actuators are discussed, and its controller is designed. A mechatronic model that expresses the controlled tracking error as function of the vehicle dynamics and the actuator characteristics is developed. This model is used by the linear quadratic regulator approach to identify the mechatronic rail vehicle proportional–integral–derivative controller’s gains. The mechatronic rail vehicle comfort is evaluated in terms of the passenger displacement, acceleration and frequency as a response of a rail irregularities caused by a lateral and two vertical track irregularities. The simulations of vibration analysis are obtained in time and frequency domains and compared with railway vehicle status. The robustness of the designed mechatronic rail vehicle is verified by simulations, carried out for the cases of car body mass variations. The results show the effectiveness of the proposed mechatronic rail vehicle design which improves significantly the transportation of passengers.

scholarly journals Examining the movement differences in the behavior of normal and rack railway vehicle

2019 ◽  
Vol 4 (1) ◽  
pp. 96-103
Author(s):  
Andor Nagy ◽  
István Lakatos
Keyword(s):  
Mechanical Model ◽  
Railway Vehicle ◽  
Vehicle System ◽  
The Many ◽  
Movement Differences ◽  
Railroad Vehicle

The rack railway is a special type of railroad. There weren”t much built worldwide, and their number is decreasing. Now, in Budapest, there is a possibility to create an interoperable vehicle, based upon the experience gained from the previously operated line, and all the research regarding its unique characteristics. One from the many important sector of its operation, is the rail/rack/vehicle system. Its mechanical model is far more complex than a traditional railroad vehicle. We will demonstrate its behaviorial differences from a traditional railroad vehicle.

scholarly journals Research on Low-Frequency Swaying Mechanism of Metro Vehicles Based on Wheel-Rail Relationship

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yixuan Shi ◽  
Huanyun Dai ◽  
Qunsheng Wang ◽  
Lai Wei ◽  
Huailong Shi
Keyword(s):  
Ride Comfort ◽  
Low Frequency ◽  
Railway Vehicle ◽  
Initial Contact ◽  
Lateral Direction ◽  
Vehicle System ◽  
Locus Method ◽  
Multibody Dynamic ◽  
Hunting Frequency ◽  
Equivalent Conicity

For the worn state of the wheel, metro vehicles often suffer a serious carbody swaying issue, which causes the lateral stability of the vehicle to exceed the limit and affects the ride comfort. An experimental test was carried out on this investigation to study the carbody swaying of the metro vehicle. The field results show that the vehicle system vibrates at around 2.5 Hz in the lateral direction, which leads to the low-frequency swaying on the carbody. In order to explore the formation mechanism of the carbody low-frequency swaying and its relationship with the geometry matching of wheel-rail contact, measured rail and wheel profiles are employed to present a comparative analysis with respect to the initial contact geometry. A multibody dynamic railway vehicle system is established further. Time-domain simulations state that the 2.5 Hz vibration on the carbody belongs to the natural frequency of the vehicle, and the amplitude is larger for the measured wheels than that of the standard wheel profiles. By using the root-locus method, it can be determined that the 2.5 Hz vibration corresponds to the upper swaying mode of the carbody. With the increase in the wheel-rail equivalent conicity, the hunting frequency of bogie increases gradually, which converts frequency with the upper swaying frequency of carbody and leads to carbody low-frequency swaying.

Vehicle System Modeling for HEV Systems Development

2007 ◽  
Author(s):  
Judy Che ◽  
Mark Jennings
Keyword(s):  
System Modeling ◽  
Model Development ◽  
System Model ◽  
Modeling Framework ◽  
Modeling Tools ◽  
Conventional Vehicle ◽  
System Models ◽  
Vehicle System ◽  
Development Processes ◽  
Component Models

The sheer complexity of engineering propulsion systems for hybrid electric vehicles (HEV) demands the use of model-based development processes supported by comprehensive, robust vehicle system models. A Vehicle System Modeling (VSM) process has been developed to provide high-quality, application-appropriate vehicle system models in time to support critical HEV engineering activities. The process seeks to manage the complexity of the large number of model variants that are required to support a vehicle program. Additionally, it drives model development and aligns modeling activities with program timing. This paper describes the key elements of the VSM process and presents an application example. The application example illustrates the process by which a highly detailed HEV system model is created from an initial, base conventional vehicle system model via integration of high fidelity component models into a re-usable vehicle system modeling framework. The component models come from a variety of modeling tools and environments, which introduces additional complexity that must be managed. Results generated from the model show the complex system interactions that must be addressed by the vehicle control strategy. This re-enforces the notion that such modeling is required to achieve robust system designs.

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