Unconventional Bogie Designs - Their Practical Basis and Historical Background

This paper deals with the design concepts for steerable bogies. A brief historical background is given and the modern design basis generated by the creep theory is summarised with regard to curving performance and dynamic stability of two- and three-axle bogies. The basic structural elements used for trailing and motorised steerable bogies are illustrated. Experience gained with some recent designs of self-steering and forced-steering bogies is discussed and achievable stability and curving performances are quoted.     

Unconventional Bogie Designs - Their Practical Basis and Historical Background

SUMMARY

This paper deals with the design concepts for steerable bogies. A brief historical background is given and the modern design basis generated by the creep theory is summarised with regard to curving performance and dynamic stability of two- and three-axle bogies. The basic structural elements used for trailing and motorised steerable bogies are illustrated. Experience gained with some recent designs of self-steering and forced-steering bogies is discussed and achievable stability and curving performances are quoted.     

Railway Vehicles With Generic Bogies Capable of Perfect Steering

The general form of the equations of motion of a symmetric railway vehicle with two unsymmetric two-axle bogies is derived. The equations include a generic elastic stiffness matrix that describes the nature and configuration of the structural connections between the various components of the vehicle. This matrix satisfies the condition for perfect steering (without generating creep forces) on uniform curves and the necessary condition for dynamic stability derived in previous work. The paper shows the application of these basic conditions to a class of generic unsymmetric bogies. The analysis has as its objective the derivation of the simplest rather than the most general configuration that meets the conditions imposed. The results are related to past and current practice. It is shown that perfect steering, with stability at low speeds, can be achieved by means of passive suspension elements not employing linkages, and that it is possible to simplify existing steering arrangements.     

Railway Vehicles With Generic Bogies Capable of Perfect Steering

SUMMARY

The general form of the equations of motion of a symmetric railway vehicle with two unsymmetric two-axle bogies is derived. The equations include a generic elastic stiffness matrix that describes the nature and configuration of the structural connections between the various components of the vehicle. This matrix satisfies the condition for perfect steering (without generating creep forces) on uniform curves and the necessary condition for dynamic stability derived in previous work. The paper shows the application of these basic conditions to a class of generic unsymmetric bogies. The analysis has as its objective the derivation of the simplest rather than the most general configuration that meets the conditions imposed. The results are related to past and current practice. It is shown that perfect steering, with stability at low speeds, can be achieved by means of passive suspension elements not employing linkages, and that it is possible to simplify existing steering arrangements.     

Simulation of active steering control for curving under traction in hauling locomotives

Active steering control in the form of secondary yaw control (SYC) and actuated wheelset yaw (AWY) have been in prototype development. This paper presents a new active steering bogie design, actuated yaw force steering (AY-FS), that is able to steer under high traction loads in tight curves. The AY-FS bogie design is compared with the AWY design. The steering performance AWY under high traction loads has not been previously reported. This paper examines five control methods, three for AWY and two for AY-FS bogies and assesses the traction curving and stability control performance of the alternative designs and control methods compared with each other and to passive steering bogie designs. The curving performance results showed considerable advantage in the proposed AY-FS bogies over the AWY. It was shown that control must be applied to both the yaw angle and the steering angle of the bogie to achieve the best traction steering performance which was not possible with the AWY bogies. The proposed new bogie designs of AY-FS overall give better traction curving and stability performance than the AWY designs.     

Dynamics of Automated Guideway Transit Vehicle with Single-axle Bogies

Summary The steering type of a mechanical guidance system has been used for Automated Guideway Transit (AGT) system in Japan. Recently, the single-axle bogie system has developed for AGT vehicle and applied to Yurikamome 7200 type vehicle. This paper describes dynamic characteristics of AGT vehicle with single-axle bogies. Introducing a nonlinear, 15 degree-of-freedom dynamic model, a computer simulation study on the lateral motion of the AGT vehicle with single-axle bogies are carried out. In order to show the dynamic characteristics of the single-axle bogie clearly, it is compared to that of the AGT vehicle with conventional steering system. The simulation study with actual vehicle parameters shows that single-axle bogie has suitable characteristics for AGT system. The multi-body dynamics modeler, DADS, is used to build the dynamic model of AGT vehicle with single-axle bogies and this is used to demonstrate the vehicle motion in actual guideway. Obtained results are compared to that of the field test. It is shown that the vehicle dynamic response can be obtained in realistic situation by using multibody dynamics code, that is useful for designing both vehicle and guideway.     

Dynamics of Automated Guideway Transit Vehicle with Single-axle Bogies

Summary The steering type of a mechanical guidance system has been used for Automated Guideway Transit (AGT) system in Japan. Recently, the single-axle bogie system has developed for AGT vehicle and applied to Yurikamome 7200 type vehicle. This paper describes dynamic characteristics of AGT vehicle with single-axle bogies. Introducing a nonlinear, 15 degree-of-freedom dynamic model, a computer simulation study on the lateral motion of the AGT vehicle with single-axle bogies are carried out. In order to show the dynamic characteristics of the single-axle bogie clearly, it is compared to that of the AGT vehicle with conventional steering system. The simulation study with actual vehicle parameters shows that single-axle bogie has suitable characteristics for AGT system. The multi-body dynamics modeler, DADS, is used to build the dynamic model of AGT vehicle with single-axle bogies and this is used to demonstrate the vehicle motion in actual guideway. Obtained results are compared to that of the field test. It is shown that the vehicle dynamic response can be obtained in realistic situation by using multibody dynamics code, that is useful for designing both vehicle and guideway.     

The Steering Characteristics of Multiple Axle Bogie Systems

Legislation limits the load that may be transferred to the roadway by the axies of a commercial vehicle and this has resulted in the development of multi axle bogies for both the tractor and trailer units of articulated vehicles and at the rear of rigid vehicles, some of these bogies contain self steering or articulation steered axles

Experience shows that the tyre wear characteristics of multi axle bogies may be unsatisfactory. The paper analyses the role of such bogies in the context of vehicle handling and shows how the lateral tyre forces vary between the axles. An hypotheses relating the forces in a steady state turn to wear is given. The analysis may also be applied to the general case of vehicle handling.     

Theoretical Comparison Between Different Configurations of Radial and Conventional Bogies

This article compares the dynamic behaviour of different configurations of radial and conventional two-axle bogies. In general, the design parameters for a better curve negotiation are not compatible with those for good stability. As the main target of this article is to compare the curving performances of different bogies under the same design basis, several bogie configurations with the same level of stability, obtained by choosing proper primary suspension stiffnesses, have been used. The comparison includes a conventional bogie and three radial bogies with differing self-steering and forced-steering principles in three different passenger services: High Speed, Regional and Mass Transit. The analysis has been concentrated on parameters such as stability, lateral wheel-track forces in curve and wheel wear indices. The results show that the radial bogie configurations studied do not make significant contributions in general applications with regard to a conventional bogie. It is only under specific running conditions and types of service that some radial bogie configurations provide advantages with respect to the conventional bogie.     

Theoretical Comparison Between Different Configurations of Radial and Conventional Bogies

This article compares the dynamic behaviour of different configurations of radial and conventional two-axle bogies. In general, the design parameters for a better curve negotiation are not compatible with those for good stability. As the main target of this article is to compare the curving performances of different bogies under the same design basis, several bogie configurations with the same level of stability, obtained by choosing proper primary suspension stiffnesses, have been used. The comparison includes a conventional bogie and three radial bogies with differing self-steering and forced-steering principles in three different passenger services: High Speed, Regional and Mass Transit. The analysis has been concentrated on parameters such as stability, lateral wheel-track forces in curve and wheel wear indices. The results show that the radial bogie configurations studied do not make significant contributions in general applications with regard to a conventional bogie. It is only under specific running conditions and types of service that some radial bogie configurations provide advantages with respect to the conventional bogie.     

The Steering Characteristics of Multiple Axle Bogie Systems

SUMMARY

Legislation limits the load that may be transferred to the roadway by the axies of a commercial vehicle and this has resulted in the development of multi axle bogies for both the tractor and trailer units of articulated vehicles and at the rear of rigid vehicles, some of these bogies contain self steering or articulation steered axles

Experience shows that the tyre wear characteristics of multi axle bogies may be unsatisfactory. The paper analyses the role of such bogies in the context of vehicle handling and shows how the lateral tyre forces vary between the axles. An hypotheses relating the forces in a steady state turn to wear is given. The analysis may also be applied to the general case of vehicle handling.     

Comparative stability of bogie vehicles with passive and active guidance as influenced by friction and traction

The stability of four bogie configurations is considered for a range of friction coefficients and traction ratios. The basis of comparison is the vehicle with conventional solid-axle railway wheelsets mounted in bogies with relatively stiff plan-view suspension. As improved performance of the wheelset in guidance can be achieved with various forms of passive and active guidance, bogies with yaw relaxation, with conventional wheelsets and active stabilisation and with independent wheels and active guidance are considered. Stability of each of these configurations is studied using a full nonlinear solution of the equations of motion. It is shown that the stability of the passive bogie configurations is very robust in the presence of traction and braking and variations of friction and that this is also true for an actively guided bogie with independent wheels. However, for a bogie with conventional wheelsets and active stabilisation, creep saturation effects can reduce stability significantly.     

微型汽车操纵稳定性问题探讨

运用汽车操纵动力学理论，结合微型汽车的结构特点和生产特点，从设计，制造，调整等几个方面对微型汽车普遍存在的转向沉重，回正不好，直线行驶跑偏，路感差，轮胎差异磨损等操纵稳定性问题进行了全面系统的分析研究，同时对汽车直线行驶稳定试验及评价方法进行了初步探讨。     

A semi-active control suspension system for railway vehicles with magnetorheological fluid dampers

The high-speed train has achieved great progress in the last decades. It is one of the most important modes of transportation between cities. With the rapid development of the high-speed train, its safety issue is paid much more attention than ever before. To improve the stability of the vehicle with high speed, extra dampers (i.e. anti-hunting damper) are used in the traditional bogies with passive suspension system. However, the curving performance of the vehicle is undermined due to the extra lateral force generated by the dampers. The active suspension systems proposed in the last decades attempt to solve the vehicle steering issue. However, the active suspension systems need extra actuators driven by electrical power or hydraulic power. There are some implementation and even safety issues which are not easy to be overcome. In this paper, an innovative semi-active controlled lateral suspension system for railway vehicles is proposed. Four magnetorheological fluid dampers are fixed to the primary suspension system of each bogie. They are controlled by online controllers for enhancing the running stability on the straight track line on the one hand and further improving the curving performance by controlling the damper force on the other hand. Two control strategies are proposed in the light of the pure rolling concept. The effectiveness of the proposed strategies is demonstrated by SIMPACK and Matlab co-simulation for a full railway vehicle with two conventional bogies.     

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.     

4WS汽车操纵稳定性建模和仿真研究

从改善汽车操纵稳定性角度出发,全面考虑轮胎载荷、转向系等对四轮转向汽车操纵稳定性的影响,建立4WS（4 Wheel Steering System）整车操纵稳定模型。并用Matalab/simulink进行了模拟仿真研究。比较性地研究汽车在低速和高速时控制方式的特点和不同之处。本模型为4WS汽车设计改进优化提供一种手段和方法,同时,为4WS汽车理论研究和试验校核提供了参考。     

混合动力微型商务车动力系统的匹配计算

针对某国产微型商务车的混合动力车型开发的初步设计要求,结合原车参数,运用汽车理论相关知识,简单有效地计算出满足该车的动力系统参数,并选择合适的工况对初步设计进行仿真研究,为混合动力车型的开发提供了动力系统匹配方案。     

千米斜拉桥设计关键技术探讨

对千米级大跨度斜拉桥的结构体系及关键构件设计、结构的几何非线性分析、稳定分析、动力分析以及车桥动力相互作用进行初步探讨。     

Application of Analytic Hierarchy Process to Stochastic Robustness Synthesis of Integrated Vehicle Controllers

This paper deals with the robust design procedure of integrated vehicle dynamics controller based on Stochastic Robustness Synthesis with use of a rational decision making process of the controller parameters. The basic control structure that integrates four-wheel steering and four-wheel torque control is determined using a nonlinear predictive control theory. The Analytic Hierarchy Process, a basic approach to decision making, is applied to determine the weight coefficients of robustness evaluation function of the controller. The desired vehicle dynamic performance is described as four-layer hierarchy structure and the design priority is determined with respect to several design criteria. The proposed design process produced a control system with excellent stability and performance robustness to vehicle parameter variations.     

Development of a systematic and practical methodology for the design of vehicles semi-active suspension control system

In this paper, a novel systematic and practical methodology is presented for design of vehicle semi-active suspension systems. Typically, the semi-active control strategies developed to improve vehicle ride comfort and stability have a switching nature. This makes the design of the controlled suspension systems difficult and highly dependent on an extensive trial-and-error process. The proposed methodology maps the discontinuous control system model to a continuous linear region, where all the time and frequency design techniques, established in the conventional control system theory, can be applied. If the semi-active control system is designed to satisfy some ride and stability requirements, an inverse mapping offers the ultimate control law. At the end, the entire design procedure is summarised in six steps. The effectiveness of the proposed methodology in the design of a semi-active suspension system for a Cadillac SRX 2005 is demonstrated with road tests results. Real-time experiments confirm that the use of the newly developed systematic design method reduces the required time and effort in real industrial problems.