Bogie System Research Articles

Safety Assessment of Complex Electromechanical Systems Based on Hesitant Interval-Valued Intuitionistic Fuzzy Theory

This paper proposes a novel framework for assessing the system safety of complex electromechanical systems (CEMSs). From the perspective of system topology, the fault pervasion probability (FPP) is first proposed to analyze fault propagation mechanisms in combination with historical failure data. This approach can easily identify all failure propagation paths and rapidly locate fault nodes, thereby providing a valuable reference for maintenance engineers. To overcome the influence of subjective factors, the hesitant interval-valued intuitionistic fuzzy element (HIVIFE) is used to describe the failure consequences of components and fault paths. Then, a system safety indicator is proposed to measure the system state and provide support to managers and operators through integration of the failure consequences based on the hesitant interval-valued intuitionistic fuzzy Choquet integral (HIVIFCI). The bogie system of a high-speed train is selected as a case study to verify the effectiveness and applicability of the proposed approach. The results indicate that the proposed approach can (i) achieve a more accurate result for system safety assessment and (ii) identify all possible fault propagation paths. This study provides a basis for formulating maintenance strategies and reducing accident losses, which have important theoretical value and practical significance.

The influence of transom pipe gap on the resonance response in motorized bogie and traction motor system

The influence of transom pipe gap on the resonance response in motorized bogie and traction motor system

Human factor analysis for railway coach and bogie maintenance using principal component analysis and factor analysis

One of the major challenges of railway transportation is to maintain the coach and bogie system for ensuring safety of passengers and goods, and maintain punctuality. In this context, there is a need to study the maintenance activities as well as humans involved in it. The present work aims to identify and analyse human factors responsible for coach and bogie maintenance of railway system. Thirty six human factors were identified. Principal component analysis (PCA) and factor analysis (FA) are used here. Three principal components were identified which represents 99% of the variance in the whole dataset. Factor analysis is performed on these three principal components to find most important factors based on individual factor loadings. Human machine interface, working environment, shift patterns, safety cultures, leadership, time pressure, situational awareness, perception, interpretation and training procedure were found to be few very important human factors.

Nonlinear stability analysis of motor bogies for high-speed trains

The traction motor flexibly suspended on the bogie frame is conducive to the lateral dynamic performance of high-speed trains. At present, most of the researches about the influences of suspension parameters of the traction motor on the stability of the bogie are limited to the linear system. In this paper, according to the suspension mode of the traction motor of a certain type of high-speed train in China, the dynamic equations of the motorized bogie with eight degrees of freedom are derived, and the nonlinear stability of the bogie system is analyzed. The bifurcation diagrams of the bogie system with different motor suspension parameters are obtained by using the continuation algorithm, and the linear and nonlinear critical speeds of the system are studied. The study shows that the suspension stiffness, damping coefficient, and the mass of the motor significantly affect the critical speeds of the bogie system. Then the mechanisms of the influence of suspension parameters on the linear and nonlinear critical speeds of the bogie are analyzed by the root locus method and Hopf bifurcation normal form theory, respectively.

Bifurcation behaviors of a high-speed bogie system with and without yaw dampers

In this paper the bifurcation behaviours and chaotic motions of a high-speed bogie system with and without yaw dampers are investigated. Non-smooth rail/wheel contact relation is considered in these models. And the bifurcation diagrams are constructed with gradually increasing and decreasing the speed of the bogie model under certain initial conditions. Subcritical Hopf bifurcation is found in both models, where the stationary equilibria and limit cycles coexist. Since the coexistence of multiple solutions, jumps and hysteresis caused by different levels of disturbances are found. Chaotic motions are found in the model without yaw dampers at a higher running speed.

System Reliability Assessment Based on Failure Propagation Processes

One or several component failures may lead to more related component malfunction and ultimately cause system reliability reduction. Based on this, we focus on the assessment system reliability of complex electromechanical systems (CEMSs) in a fault-propagation view. First, failure propagation model taking into consideration failure data based on network theory and improved polychromatic sets is proposed for system reliability evaluation. From the node point of view, system effectiveness index is constructed to investigate the variation of efficiency of the holistic network. Subsequently, from the system’s perspective, system reliability measurement is provided and estimated in combination with system effectiveness index and failure propagation models. Finally, the application of proposed method to a bogie system of high-speed train assesses system reliability, and meanwhile, the effectiveness of the proposed method is able to be illustrated.

The influence of the perturbation of the wheel rotation speed on the stability of a railway bogie on steady curve sections of a track

ABSTRACTBased on the theory of non-linear dynamic systems, the influence of the perturbation of the wheel rotation speed on the quasi-steady curved motions of a two-axle railway bogie system with a realistic wheel/rail contact relation is investigated in this paper. Since the wheel/rail contact relation is non-linear, it is tabulated in a wheel/rail contact table. The bifurcation diagram of the bogie system is constructed with gradually increasing and decreasing speed in the speed range . A supercritical Hopf bifurcation, where the stable non-trivial stationary solution loses its stability, is found in both models with and without perturbation of the wheel rotation speed. In the model without perturbation of the wheel rotation speed, the first chaotic motions develop at the speed where the wheel flange contact starts. A period-doubling cascade of the bogie system through pitchfork bifurcations, which explains the transition from periodic solutions to chaotic motions of the bogie system, is found. Several jumps happen at higher speeds because of the coexistence of multiple attracting solutions, which should be avoided. A comprehensive investigation of the hysteresis phenomena is made. However, in the model with a perturbation of the wheel rotation speed, no chaotic motions are found.

Multistate Reliability Evaluation of Bogie on High Speed Railway Vehicle Based on the Network Flow Theory

Bogie is one of the most major mechanical part of railway train. Its security and reliability are of paramount importance. Since research in this field is still on the early stage, which focus on either mechanical structure without condition or binary coherent systems. A multistate network flow model has been proposed in this paper with consideration of components degradation level and functional interaction between them. Firstly, the structure and function of the bogie for CRH3 were made a detailed introduction. Then transmission paths of three types force on bogie were study to determine the network strcture. Different from other papers, arcs represent the components and nodes are the transitive relation. Arc capacity tends to be confirmed easily with utilization of performance deterioration of elements on bogie involved in force tranferring. Flow rate of each arc depends on both component' health status and the task it undertakes. Furthermore, the minimal paths (MPs) method and the recursive sum of disjoint products (RSDP) with ordering heuristics are used for system reliability calculation; and the relative probability importance of each basic component and system reliability with and without forehead information are given at last. The results show that the network flow model works well on CRH3 bogie, and can support as guidance of bogie system design, daily system operation and predictive maintenance.

A Study on the Individual Control Method Comparing the Lateral Displacement Control of Front Wheel and Rear Wheel of IRWs System

This paper proposes an algorithm to obtain better results in the integrated control by reflecting the characteristics of the individual control of the front wheel and the rear wheel of tram systems. In the case of the surface transportation, which has recently been introduced, severely curved driving performance is required for the downtown. It is possible to decrease the curve radius and to improve the performance of the straight driving with the individual torque control. Therefore, the individual torque control performance of the motor is the most important point of the surface transportation. The front and rear wheels have different torque characteristics, and the length of the bogie during curve travel also affects these results. This system is more controllable than the system with 1Controller 4Motor (1C4M) in the form of 2C4M with the front and rear wheels being individually controlled, allowing more precise control because of its higher degree of freedom. Because of this individually controlled characteristic, it is possible to control more precisely in the integrated control considering the characteristics of the front wheel and the characteristics of the rear wheel. The validity of the proposed control algorithm is verified by experimental results using a small-scale bogie system.

A Study on the Control Method of Lateral Displacement and Yaw Angle in Curved Driving of IRWs System

This paper proposes an optimal control algorithm through lateral displacement and yaw angle in curved road of shallow-depth subway systems. In the case of the surface transportation, which has recently been introduced, curved driving performance is required for the downtown. The existing research works are the main research theme of the lateral displacement restoration control, but there is a limit to smooth operation when the curve is run only by receiving the lateral information. However, when the yaw angle displacement information is obtained, it is possible to consider the turning angle of the vehicle while the vehicle is driving in a curved road. However, it is difficult to control because the change of yaw angle is more sensitive than lateral drift. Therefore, this paper suggests an algorithm that uses yaw angle displacement control. The validity and usefulness of the proposed control algorithm is verified by experimental results using a small-scale bogie system.

On the Singularity Theory Applied in Rail Vehicle Bifurcation Problem

The application of Hopf bifurcation is essential to rail vehicle dynamics because it corresponds to the linear critical speed. In engineering, researchers always wonder which vehicle parameters are sensitive to it. With the nonlinear singularity theory's development, it has been widely applied in many other engineering areas. This paper mainly studies the singularity theory applied in nonlinear rail vehicle dynamics. First, the bifurcation norm forms of wheelset and bogie system are, respectively, deduced. Then the universal unfolding is obtained and the influences of perturbation on bifurcation are investigated. By the analysis of a simple bar-spring system, the relationship between the unfolding and original perturbation parameters can be found. But this may be difficult to calculate for the case in vehicle system because of higher degrees-of-freedom (DOFs) and indicate that can explain the influence of all possible parameters perturbations on vehicle bifurcation.

Hunting patterns and bifurcation characteristics of a three-axle locomotive bogie system in the presence of the flange contact nonlinearity

This paper considers a three-axle railway locomotive bogie running on a straight track and presents pattern diversity and bifurcation characteristics of its hunting behaviors at forward speeds higher than the hunting critical speed. Poincaré sections describing the cycle characteristic and wheel-rail impacts of the bogie system are defined according to the geometric structure of phase space of the dynamical system for carrying out multi-target and multi-parameter co-simulation analysis. The influences of dynamical parameters of the locomotive bogie on the wheel–rail impacts are studied and some important features of hunting behaviors in the presence of the flange contact nonlinearity are found. A series of grazing bifurcations induce the pattern diversity of hunting behaviors. The impacts of the middle and trailing wheelsets on the rail fall behind that of the leading wheelset, and the impact lag of the hunting motion of the middle wheelset is the most obvious of the three wheelsets. The top branch of impact velocity bifurcation diagram of period 1 hunting motion of the trailing wheelset is slightly lower than those of the leading and middle wheelsets. The instability speed of period 1 hunting-impact motion of the bogie system with worn wheelsets is lower than that with new wheelsets and the impact velocities of the worn wheelsets on the rail become smaller. A method of reasonable matching of primary suspension parameters, which brings about the substantial increase of the instability speed of periodic hunting behavior in the presence of the flange forces, is presented and the matching effect is verified by bifurcation diagrams of impact velocities of the new and worn leading wheelsets versus the forward speed.

A codimension two bifurcation in a railway bogie system

In this paper, a comprehensive analysis is presented to investigate a codimension two bifurcation that exists in a nonlinear railway bogie dynamic system combining theoretical analysis with numerical investigation. By using the running velocity V and the primary longitudinal stiffness $$K_{1x}$$ as bifurcation parameters the first and second Lyapunov coefficients are calculated to determine which kind of Hopf bifurcation can happen and how the system states change with the variance of the bifurcation parameters. It is found that multiple solution branches both stable and unstable coexist in a range of the bifurcation parameters which can lead to jumps in the lateral oscillation amplitude of the railway bogie system. Furthermore, reduce the values of the bifurcation parameters gradually. Firstly, the supercritical Hopf bifurcation turns into a subcritical one with multiple limit cycles both stable and unstable near the Hopf bifurcation point. With a further reduction in the bifurcation parameters two saddle-node bifurcation points emerge, resulting in the loss of the stable limit cycle between these two bifurcation points.

Dynamic stability of vibrations and critical velocity of a complex bogie system moving on a flexibly supported infinity track

The paper studies vibrations of a complex bogie system moving along a high order shear deformable beam on a viscoelastic foundation. The complex bogie system is modeled by elastically connected rigid bars on identical supports. An elastic coupling between the bars is introduced to simulate a rigid or flexible (transverse or/and rotational) connection. Identical supports are modeled as a system of springs and dashpots attached to the bars on one side, which interact with the beam through the concentrated masses on the other side. It is assumed that the masses and the beam are always in contact. A new analytically determined critical velocity of the system is presented. The paper analyzes the case when the complex bogie system exceeds the minimum phase velocity of waves in the beam, which may lead to the vibration of the system becoming unstable. The effect of the elastic coupling between the bars on the stability of the system is also analyzed. The instability regions are found for the complex bogie system by applying the principle of the argument and the D-decomposition method.

Numerical study on the aerodynamic noise characteristics of CRH2 high-speed trains

The aerodynamic noise of high-speed trains not only causes interior noise pollution and reduces the comfort of passengers, but also seriously affects the normal life of residents. With the increase of running speed of trains, aerodynamic noises will be more than wheel-rail noises and become the main noise source of high-speed trains. This paper established a computational model for the aerodynamic noise of a CRH2 high-speed train with 3-train formation including 3 train bodies and 6 bogies, adopted the detached eddy simulation (DES) to conduct numerical simulation for the flow field around the high-speed train, applied Ffowcs Williams-Hawkings acoustic model to conduct unsteady computation for the aerodynamic noise of high-speed trains, and analyzed the far-field aerodynamic noise characteristics of high-speed trains. Studied results showed: The main energy of the complete train was mainly within the range of 613 Hz-2500 Hz when the high-speed train ran at the speed of 350 km/h. In the whole frequency domain, it was a broadband noise. Regarding the longitudinal observation point which was 25 m away from the center line of track and 6m away from the nose tip of head train, the sound pressure level of total noises reached the maximum value 88.9 dBA. The maximum sound pressure level of the noise observation point which was 7.5 m away from the center line of track was around the first bogie of head train. Various components made different contributions to the aerodynamic noise of the complete train, and the order was head train, mid train, bogie system (6 bogies) and tail train. The first bogie of head train made the greatest contribution to bogie system and was the main aerodynamic noise source of the complete train.

Pareto-optimization of complex system architecture for structural complexity and modularity

Due to ever-increasing complexity of cutting-edge engineering systems, the need for managing structural complexity and modularity of such systems is becoming important. The complexity of the overall system architecture is mostly decided during the initial concept generation stage, when configurations of major modules within the system are determined. In this paper, we present a multi-objective optimization framework for (1) minimizing the variation in complexity allocation to individual modules, while (2) maximizing for the degree of modularity. The optimization framework was applied to a case study, where a trailing bogie system for railroad train was optimized for structural complexity allocation among individual modules and overall system modularity. The modularity maximizing decomposition is shown to induce a large variation in module-level complexity distribution with a small fraction of modules sharing a disproportionately large chunk of overall system complexity, while equitable distribution of module-level complexity leads to erosion in the degree of modularity achieved for the resulting system decomposition.

Development of a bogie for running on a track having a steep gradient and sharp curves

In this study, core technologies are developed for a bogie system to enable the bogie to run on a track that has a steep gradient and sharp curves. The bogie is designed to run on a minimum curve radius of 10 m by developing independently rotating wheels and axles. It is also designed to run on a maximum gradient of 180‰ with reduced noise by developing an elastic pinion. The traction motor power required for a steep gradient is calculated and reflected in the design of the traction system. In addition, a band braking system is developed to improve the braking force while running on a steep gradient track. The developed main parts are tested to evaluate their performance and are subsequently applied to the bogie systems designed to run on a steep gradient and sharp curve tracks. The maximum load on the bogie frame is reassessed by considering the running conditions on a track that has a steep gradient and sharp curves. The safety of the bogie frame is verified through a loading test. Finally, the developed bogie system with the incorporated parts and core technologies undergoes a running test on a roller rig for evaluating its performance.

Conceptual design of high-speed semi-low-floor bogie for train-tram

Train-tram railway vehicles implement the connection between urban tramlines and the surrounding railway network. Train-tram railway vehicles, which use existing infrastructure, can help to avoid large investments in new railways or tramlines and make interchanges between city center and surrounding cities unnecessary. However, present train-tram rail vehicle cannot carry out the integration of operating by means of high speed in intercity railways with operating on small radius of curvature in inner city tramlines. This paper aims to develop a new model for solid wheelsets train-tram railway vehicles, which will not only pass the curve of 25mR radius of curvature traveling on inner city tramlines with the speed of 18 km/h, but also can travel on straight railway with 200 km/h high speed between intercity. In this paper, a new train-tram model, including five car-body and five motor bogies with ten traction motors, is addressed. Expect as a real rail vehicle testing, this study prefer virtual simulation, which is an effective way to show the rail vehicle performance, such as ride stability, ride comfort and ride safety, by means of evaluating the dynamic characteristics of rail vehicle. Moreover, Design of Experiment (DOE) method is used to optimize solid wheelsets bogie system on improving passenger comfort, safety and stability of train-tram. Parameters of components of bogie system are tuned to minimize the derailment coefficient and the ride comfort index. The results shows that the best comfort index for passenger and minimum derailment coefficient are found. The results also show that this optimized new train-tram model is reliable and practical enough to be applied on real rail vehicle design.

Component Importance Measure Computation Method Based Fuzzy Integral with Its Application

In view of the negative impact of component importance measures based on system reliability theory and centrality measures based on complex networks theory, there is an attempt to provide improved centrality measures (ICMs) construction method with fuzzy integral for measuring the importance of components in electromechanical systems in this paper. ICMs are the meaningful extension of centrality measures and component importance measures, which consider influences on function and topology between components to increase importance measures usefulness. Our work makes two important contributions. First, we propose a novel integration method of component importance measures to define ICMs based on Choquet integral. Second, a meaningful fuzzy integral is first brought into the construction comprehensive measure by fusion multi-ICMs and then identification of important components which could give consideration to the function of components and topological structure of the whole system. In addition, the construction method of ICMs and comprehensive measure by integration multi-CIMs based on fuzzy integral are illustrated with a holistic topological network of bogie system that consists of 35 components.

차량편성구성에 따른 고속화물열차의 추진 및 제동성능 분석 연구

Currently, logistics are in small quantities and in diverse forms, and the amounts are continuously increasing. Railway logistics however are losing their market share every year mainly due to low operation speed and loading time, which means the trucks are covering the most of the freights. In order to solve these situations, this paper proposed the high speed freight train as working multi-modality with other modes to make effective transshipment. The high speed freight train has maximum operation speed of 300km/h and electric power to run centralized power supply. There are large dual door system, bogie system covering fluctuating load of 15[ton], automatic loading device, ULD(unit load device) bed and ULD locking system in this freight rolling stock. We calculated the performance of powering and braking capacity for this train and proposed how many vehicles are composed of train set. The results in this paper can help to make a decision to define the technical specification of High-speed freight train for the efficiency of rail freight service.