A dynamic model for the vertical interaction of the rail track and wagon system

With the rapid development of communication, control and computer technologies in the last several decades, automatic train operation (ATO), for which the driver no longer has to cautiously operate the control handle, is emerging in many urban rail systems to replace traditional manual driving in recent years. As technology advances in railway systems, one theoretically challenging and practically significant problem is how to use the ATO system to make the current railway network more efficient with higher carrying capacity, lower cost and improved quality of service by optimized railway traffic management and train operation. In this review, we focus on this emerging technology of automatic train operation (ATO) for its theoretical development and practical implementations. Specifically, this study first presents the background of ATO technology in railways, which involves the detailed description of its development and implementation in urban metro systems, fundamental features and basic structure of a typical ATO system. Then, we present a comprehensive literature review in this area, in which the current studies are generally classified into three main aspects, i.e., train operation modeling techniques, train trajectory optimization and train speed control methods. Finally, the emerging requirements for current ATO systems and the most promising research directions in this area in the future are discussed explicitly, including (i) the practical implementation of ATO in main line and high-speed railways, (ii) the cooperative train operation methods for energy-saving issues and (iii) the integration of railway traffic control with advanced ATO technology.

Research and development of automatic train operation for railway transportation systems: A survey

This paper discusses the evolution of longitudinal train dynamics (LTD) simulations, which covers numerical solvers, vehicle connection systems, air brake systems, wagon dumper systems and locomotives, resistance forces and gravitational components, vehicle in-train instabilities, and computing schemes. A number of potential research topics are suggested, such as modelling of friction, polymer, and transition characteristics for vehicle connection simulations, studies of wagon dumping operations, proper modelling of vehicle in-train instabilities, and computing schemes for LTD simulations. Evidence shows that LTD simulations have evolved with computing capabilities. Currently, advanced component models that directly describe the working principles of the operation of air brake systems, vehicle connection systems, and traction systems are available. Parallel computing is a good solution to combine and simulate all these advanced models. Parallel computing can also be used to conduct three-dimension...

Longitudinal train dynamics: an overview

Health monitoring systems with low-cost sensor networks and smart algorithms are always needed in both passenger trains and heavy haul trains due to the increasing need for reliability and safety in the railway industry. This paper focuses on an overview of existing approaches applied for railway vehicle on-board health monitoring systems. The approaches applied in the data measurement systems and the data analysis systems in railway on-board health monitoring systems are presented in this paper, including methodologies, theories and applications. The pros and cons of the various approaches are analysed to determine appropriate benchmarks for an effective and efficient railway vehicle on-board health monitoring system. According to this review, inertial sensors are the most popular due to their advantages of low cost, robustness and low power consumption. Linearisation methods are required for the model-based methods which would inevitably introduce error to the estimation results, and it is time-...

An overview: modern techniques for railway vehicle on-board health monitoring systems

Given the constant demand for heavier, longer, faster, and more efficient rail freight vehicles, onboard fault detection systems appear as a good approach for enhanced railway asset exploitation. Real-time condition monitoring reduces inefficient preventive and reactive maintenance actions, decreases waste from replacing parts that still have a useful life, and improves availability and safety by real-time rolling stock diagnosis. There have been considerable advances in wayside monitoring applications, but these cannot achieve real-time continuous monitoring. With the price reduction and miniaturization trends of electronic devices, the cost of deploying wireless sensor networks onboard freight trains continues to become more feasible and accessible. On the other hand, the lack of onboard electric power availability on freight wagons appears as the major limitation for the implementation of these technologies. This paper reviews recent onboard condition monitoring sensors, systems, methods and techniques, aiming to define the present state of the art and its potential application for freight wagons without onboard electric power.

Onboard Condition Monitoring Sensors, Systems and Techniques for Freight Railway Vehicles: A Review

A thorough understanding of the issues that affect dynamic performance, as well as more inventive methods for controlling rail vehicle dynamics, is needed to meet the demands for safer rail vehicles with higher speed and loads. Design and Simulation of Rail Vehicles examines the field of rail vehicle design, maintenance, and modification, as well as performance issues related to these types of vehicles. This text analyzes rail vehicle design issues and dynamic responses, describes the design and features of rail vehicles, and introduces methods that address the operational conditions of this complex system. Progresses from Basic Concepts and Terminology to Detailed Explanations and Techniques. Focused on both non-powered and powered rail vehicles—freight and passenger rolling stock, locomotives, and self-powered vehicles used for public transport—this book introduces the problems involved in designing and modeling all types of rail vehicles. It explores the applications of vehicle dynamics, train operations, and track infrastructure maintenance. It introduces the fundamentals of locomotive design, multibody dynamics, and longitudinal train dynamics, and discusses co-simulation techniques. It also highlights recent advances in rail vehicle design, and contains applicable standards and acceptance tests from around the world. Design and Simulation of Rail Vehicles serves as an introductory text for graduate or senior undergraduate students, and as a reference for practicing engineers and researchers investigating performance issues related to these types of vehicles.

Design and Simulation of Rail Vehicles

Lateral force components and impacts from couplers can adversely affect wagon stability. These issues are significant in longer and heavier trains increasing the risk of wagon rollover, wheel climb, wagon body pitch, bogie pitch and wagon lift-off. Modelling of coupler angles has been added to normal longitudinal train simulation to allow comprehensive study of lateral components of coupler forces. Lateral coupler forces are then combined with centripetal inertia calculations to determine quasi-static lateral forces, quasi-static vertical forces and quasi-static bogie lateral to vertical ratio, allowing the study of stringlining, buckling and wagon rollover risks. The approach taken allows for different rolling stock lengths, overhang and coupling lengths, and allows the study of angles occurring in transitions. Wagon body and bogie pitch are also studied with enhancements added to previous modelling to allow the study of wagon lift-off.

Wagon instability in long trains

It has been determined that railway turnouts demand more maintenance than other parts of the railway track network because of large impact loads generated by the variation of wheel–rail contact conditions along the turnout and through the crossing. A method using VAMPIRE® modeling to determine the wheel impact forces due to passing turnout has been developed and is presented in this article. The simulation shows that both turnout curve and crossing have significant effect on the wheel impact forces; the vertical impact forces from the turnout case are not significantly different from the wheels traveling straight through.

The Calculation of Wheel Impact Force Due to the Interaction between Vehicle and a Turnout

Occurrences of coupler impacts combined with pitching motions in the wagon body and bogies of a 70 tonne hopper coal wagon were located in experimental data. Attempts were made to simulate these interactions using NUCARS, ADAMS/Rail and a train-wagon interaction model developed as source code. The NUCARS and Adams/Rail models were simulated using a single longitudinal force profile. The wagon was also simulated in the train-wagon interaction model using locomotive control actions and a train model reflective of the experimental program. Good agreement was demonstrated between the models but the experimental data remained problematic. Some agreement was possible for the experimental data measured for the loaded wagon. For the covering abstract see ITRD E117109.

An investigation of the effect of bogie and wagon pitch associated with longitudinal train dynamics

Railway operators are continually increasing the length and weight of heavy haul trains to achieve reduced operating costs and increase network capacity. With longer and heavier trains, it becomes increasingly difficult for human operators to control the train optimally. The three main objectives of train control are minimizing journey time, minimizing energy usage, and minimizing in-train dynamics. This article reviews published train control optimization methods used in passenger, freight, and long heavy haul trains with a view of determining which methods would be best applied to the optimization of heavy haul train control.

Mitchell McClanachan

Papers

Design and Simulation of Rail Vehicles

Wagon instability in long trains

The Calculation of Wheel Impact Force Due to the Interaction between Vehicle and a Turnout

An investigation of the effect of bogie and wagon pitch associated with longitudinal train dynamics

Current train control optimization methods with a view for application in heavy haul railways