A long-term tracking test was performed on a newly designed high-speed train with the nominal speed of 250 km/h. The wheel roughness and structural vibration were both recorded during two re-profiling cycles. The 3rd order polygonal wear was observed in the early stage. The vibration of the axlebox can be aggravated even at lower speed when the passing frequency of polygonal wear approaches the P2

Although a passive independently-rotating wheel-pair (IRW) is not well suited for curve negotiation due to an inability to provide the necessary steering, an active IRW system offers the potential to realise perfect curving with a satisfactory running stability. Simple control solutions to realise automatic steering and stability of the IRW system are proposed in this paper. In this control approach

The modelling of the wheel–rail contact is fundamental in the railway field since the contact forces directly affect vehicle dynamics, wear, safety and maintenance. In this context, the development of a realistic adhesion model able to describe degraded adhesion conditions is still an open problem because of the complex non-linear behaviour of the adhesion coefficient. To face this problem, in this

In the design of a path-tracking controller for autonomous vehicles, mediating the conflicting objectives among path-tracking, vehicle stabilisation, and low computational cost is a challenging issue. Accordingly, this paper proposes a model predictive control (MPC)-based path-following controller with steering angle envelopes. In contrast to previous MPC-based structure, in which the constraints in

In order to reveal the abnormal vibration of a newly developed 200 km/h medium-speed maglev vehicle with mid-mounted permanent magnet linear synchronous motors at specific speeds, field vibration tests at different running speeds are carried out and analysed in this paper. The accelerations of the linear motor and levitation module were measured during powered running as well as idle running. Data

Hunting stability is a long-standing research topic and has been deeply investigated due to its great influence on railway vehicle dynamic performances. Most of the existing hunting monitoring methods detect only the large amplitude hunting instability (LAHI). However, the small amplitude hunting instability (SAHI) is still hard to be detected accurately and efficiently. To face this challenging problem

Controllable suspension systems have the capability of changing suspension forces. One control approach is to define a cost function with the aim of optimising either ride comfort or handling. Such controllers are usually reactive and not pro-active. Controllers can benefit significantly by having a priori knowledge of the effect that changing the suspension settings will have on the suspension forces

This paper deals with unsteady-state brush tyre models. Starting from tyre-road contact theory, we provide a full analytical solution to the partial differential equations (PDEs) describing the bristle deformation in the adhesion region of the contact patch. We show that the latter can be divided in two different regions, corresponding to two different domains for the solution of the governing PDEs

The vibration environments of railway vehicles can be considered as the source of the vibrations in respective parts of that. With a certain vibration environment above the limit, structural cracks or component drops occur because of the vibration of axle box and bogie frame. Considering the multi-channel and non-normal characteristics of the measured environment of rail vehicles, a statistical induction

The wheel polygonisation is the harmonic wave along the wheel circumference, which has been widely reported in high-speed railway vehicles in China in recent years. The polygonization mechanism has not been fully understood yet, and this work discusses one possible mechanism through several experiments. Firstly, a field test for the CRH3 high-speed train with polygonal wheels is carried out. It is

High-order polygonal wear wheels have been detected on metro express train operating on one metro line in China, which cause fatigue failures of steel coil springs in the primary suspension. A series of tests and theory analysis were conducted to figure out the mechanism of wheel high-order polygonal wear. The wheel out-of-roundness (OOR) measurement results show that the wheels exhibit polygonal wear

In the framework of vehicle-track interaction, this work puts an emphasis on clarifying the influence of sleeper finite element types on system dynamic responses. Three sleeper element types, namely the rigid-body, extensible Euler-Bernoulli beam and solid element are used respectively in the track system modelling with detail mathematical formulations presented. The rails are modelled as Timoshenko

In order to make full use of the direct yaw control (DYC) in electric vehicles with four in-wheel motors (IWMs), this paper presents an adaptive SMC control scheme to improve the handling and stability based on a novel stability index proposed to quantitatively represent stability level. Firstly, a vehicle stability evaluation method is designed based on the front and rear tire slip angles phase plane

This paper presents original data records of linear accelerations and angular velocities of six points of a racing bicycle collected during a ‘genuine’ hands-on shimmy. The records, together with GPS, forward speed data, and action cam videos are thoroughly analysed to understand the actual motion of the bicycle and its parts, at lower (weave) and higher (wobble or shimmy) frequencies. The main goal

Pier settlement is unavoidable in bridge construction and operation processes, thus the influence of pier settlement on the train-track-bridge coupled system becomes a classic and meaningful topic in railway engineering. Aiming at this practical problem, three interesting works are conducted in this paper: (a) a detailed single-pier settlement model (SPSM) is developed with analytic method; (b) a multi-pier

A low-cost experimental-numerical method for the prediction of on-road comfort of city bicycles is presented. Experimental tests are performed by exciting the wheels of the bicycle with impulsive vibrations and measuring the frequency response functions (FRFs) between different sensitive points of the bicycle (i.e. seatpost and steerer tube) and the wheels. Laboratory tests are carried out with the

The wheel-rail contact stress solution is the precondition for many wheel-rail contact problems, such as wheel-rail contact fatigue, plastic deformation and wear, etc. However, vehicle-track interaction generally shows a high degree of randomness due to the uncertainty of excitations, e.g. track irregularities, in the estimation of wheel-rail contact point positions and contact stresses. Moreover,

ABSTRACT In this paper, we analyse the performance of a model predictive controller for coordination of connected, automated vehicles at intersections. The problem has combinatorial complexity, and we propose to solve it approximately by using a two stage procedure where (1) the vehicle crossing order in which the vehicles cross the intersection is found by solving a mixed integer quadratic program

(2020). Theme issue on connected and automated road vehicles. Vehicle System Dynamics: Vol. 58, Connected and Automated Road Vehicles guest edited by: Gabor Orosz and Ilya Kolmanovsky, pp. 669-671.

A cab-based track monitoring system has been developed which makes use of the existing on-board GSM-R cab radio present in the majority of trains operating in the UK. With the addition of a low-cost sensor, type, location and severity of the track defects are reported using the system. The system improves safety and network performance by efficiently directing maintenance crews to the location of defects

The dynamic performance of the vehicle is improved when the bogie of a monorail vehicle passes through the curve in the radial position. This study aimed to derive the analytical relationship between the torque generated by the auxiliary guiding device and the yaw angle between the bogie and the vehicle body based on the geometric relationship between the auxiliary guiding device of the straddle monorail

(2020). Correction. Vehicle System Dynamics: Vol. 58, No. 4, pp. 657-667.

This study presents original new results on measured whole-body vibration (WBV) on passenger’s seat surface and seat base as a function of measured road unevenness in the longitudinal direction. Measurements were provided on nine different cars of six categories operated on about 1860 km of road network. Root mean square (RMS) of the frequency-weighted acceleration was used to quantify the WBV. The

The shift quality of two-speed planetary of electric vehicle is closely related to the characteristics of shift oil pressure. In this paper, the smooth shift control strategy of electric vehicle with two-speed planetary transmission is studied. Firstly, the dynamic models of the two-speed planetary gear train, the shift oil pressure of the hydraulic system and the clutch friction torque are established

Accurately estimating the coefficient of adhesion (CoA) is important to the safety, maintenance, operation and wheel–rail dynamics of railway systems. Studies have reported the influence of various parameters on the CoA and developed subsequent models, but parameter contribution or model estimation accuracy has not been systematically examined. Therefore, this study aims to quantitatively compare the

Monitoring the condition of suspension systems is significant to ensure the safe operation of modern railway vehicles. For this purpose, an online modal identification scheme, denoted as Correlation Subset based Stochastic Subspace Identification (CoS-SSI) is proposed in this paper to monitor the suspension conditions. Because of the widespread of the dynamic contact status between wheel and track

Reducing railway vehicles’ three-dimensional (3D) elastic vibration is needed to improve passenger comfort. This paper presents a 3D analytical model and parameter determination method for the elastic vibration of a carbody. The carbody is modelled as a simple box-type structure consisting of an anisotropic 3D elastic body treated as a continuous system. This model can express complicated 3D elastic

As a significant active safety technology towards fully autonomous driving, driver-automation co-piloting provides a new thinking for enhancing vehicle active safety and relieving driver’s workload. However, the preview pattern divergence between driver and steering assistance system (SAS) may give rise to serious steering conflicts, which reduces driver’s faith in SAS, cause him/her to turn off it

ABSTRACT Most existing models of driver steering control do not consider the driver's sensory dynamics, despite many aspects of human sensory perception having been researched extensively. The authors recently reported the development of a driver model that incorporates sensory transfer functions, noise and delays. The present paper reports the experimental identification and validation of this model

Mode transition plays an important role in the operation of hybrid electric vehicles. The clutch is a key actuator for mode transition, but friction resulting from its use makes it difficult to achieve seamless mode transition. Moreover, as is usual in an electromechanical coupling system, the hybrid powertrain may exhibit complex dynamic behaviours as operating parameters change during mode transition

A complete track-vehicle-pantograph-catenary (TVPC) coupling dynamics model is presented and several elaborate simulation cases are set to analyse the effect of vehicle body vibration on the pantograph-catenary system (PACS). The catenary is described by a finite-element model while the pantograph, vehicle and track are described by a multi-body model. In addition, different track irregularities are

Traction or braking operations are usually applied to the motor cars or locomotives for acceleration and deceleration, especially in perilous mountain high-speed railways that have complex and large gradient sections. Under such a circumstance, the wheel-rail longitudinal interactions may become more intense, which could induce longitudinal impact on the track structure. In this paper, some new concepts

The automation of vehicle steering is necessary in order to guarantee safe vehicle following in short-distance vehicle following applications. A necessary (safety) requirement for such automation strategy is lateral string stability. In this paper, a design for cooperative lateral controllers is proposed that yields a laterally string-stable platoon. The dynamics of the vehicles in the platoon are

When aiming to improve the performance of industrial sports cars at the limits of driving dynamics, the passive vehicle setup should be tuned under consideration of the actuator configuration and the control system capabilities. To objectively quantify the performance of given vehicle settings, minimum lap times can be determined using optimal control methods. The computed trajectories can be used

This paper focuses on the development of the pneumatic CRONE suspension consisting of two different suspension architectures and a switching between them. The so called stiff architecture is oriented to the road behaviour. It enables the use of the levelling system, allowing, amongst others, the body control under driver inputs [Bouvin J-L, Moreau X, Benine-Neto A, et al. CRONE body control under driver

The state of the art of modelling, control, and optimisation is discussed for automated road vehicles that may utilise wireless vehicle-to-everything (V2X) connectivity. The appropriate tools to address safety and energy efficiency are described and the effects on traffic dynamics are highlighted. Finally, the economical and societal impacts of the deployment of connected and automated vehicles are

Different types of instability modes in tractor-trailer vehicles, including jackknifing and snaking, necessitate designing a fast and effective control strategy. In this paper, a model predictive controller (MPC) is developed to prevent these instability modes in a car-trailer vehicle as a specific form of tractor-trailer vehicles equipped with differential braking. The effectiveness of the control

(2020). Statement of retraction: lateral stiffness modelling of air spring systems in urban rail vehicles and its effect on stability and ride comfort. Vehicle System Dynamics. Ahead of Print.

(2020). Hans B. Pacejka (1934–2017): a life in tyre mechanics. Vehicle System Dynamics. Ahead of Print.

Active steering technology is an effective method to solve the contradiction between curving performance and running stability of traditional bogie. In this study, an integrated active steering device was developed to integrate wheelset constraints and actuators. In addition, to study the minimum wear number control strategy, the existence of an optimal steering level that minimises the wear number

Conventional speed planning for connected automated vehicles (CAVs) adopts an energy-centric perspective and improves fuel economy by means of reducing the power loss due to braking and operating the engine at its high efficiency region. This paper considers a simulated connected automated truck with a diesel powertrain and a selective catalytic reduction (SCR) system for the treatment of NOx emissions

In this paper, directional stability of road vehicles travelling at time-dependent forward velocity is investigated. The dynamical behaviour of the system is governed by a set of linear ordinary-differential equations with time-varying coefficients. A simple two degrees of freedom (DOF) model is considered, in order to better understand the effects of such a perturbation on the well-established bicycle

Track irregularities are perhaps the main excitations of vehicle–track systems and cause dynamic wheel–rail responses, but track irregularities and vehicle responses do not always correspond to each other. In this study, the interrelations between track irregularities and vehicle responses in a multi-scale framework were investigated using measured data. Firstly, the track irregularity and vehicle

This paper focuses on the rapid elastoplastic analyses of light rail vehicle (LRV)- benchmark viaduct system to different seismic scenarios considering the dynamic substructuring method (DSM). Combining the energy-variational principle with the vehicle-bridge interaction (VBI) system, a new framework of train-track system space dynamics is constructed. The present study has established the train-track-bridge

Discrete irregularities are a common issue occurring on locomotive wheels. The wheel roughness measured in the field sites indicates that some wheels suffer from discrete wheel irregularities, such as wheel flats or local defect. Meanwhile, the wheels exhibit obvious polygonisation. A wheel wear model is present to study the influence of discrete wheel irregularities on locomotive wheel polygonisation

Parallel hydraulic hybrid vehicles (PHHVs) integrate conventional engines with a hydraulic pump/motor (HPM) to drive the vehicle independently or in combination. To improve the comfortability and drivability during mode switching from hydraulic driving mode to engine driving mode, this paper proposes a coordinated control strategy for the engine, clutch and HPM. To capture the transient behaviour of

While several papers dealing with the kinematic of mechanisms that approximate the well-known Ackermann steering are available, apparently there are no contributions related to the effect of Ackermann steering on vehicle performance. This work focuses on the effect of Ackermann steering and parallel steering on the performance of a racing car, after a discussion on the different definitions of Ackermann

(2020). RETRACTED ARTICLE: Lateral stiffness modelling of air spring systems in urban rail vehicles and its effect on stability and ride comfort. Vehicle System Dynamics. Ahead of Print.

Active safety systems contribute significantly to the safe driving of autonomous vehicles in hazardous circumstances. However, conventional active safety systems that mainly depend on braking intervention may not yield the desired vehicle behaviour in critical situations where the tyre forces tend to saturate. Over-actuation through individually cambering the wheels provides a possibility of overcoming

Field tests were carried out to measure the wheel-rail forces of a high-speed train passing by a windbreak breach with a crosswind speed and a train speed of 32 m/s and 120 km/h, respectively. Unsteady Reynolds-averaged Navier-Stokes simulations and multibody dynamic simulations were carried out to reproduce the field test experiments. The results obtained indicated that the side force and yawing moment

The implementation of connected and automated vehicle (CAV) technologies enables a novel computational framework to deliver real-time control actions that optimise travel time, energy, and safety. Hardware is an integral part of any practical implementation of CAVs, and as such, it should be incorporated in any validation method. However, high costs associated with full scale, field testing of CAVs

In order to ensure safety and reliability of railway transportation the interest in monitoring systems is constantly increasing. These devices include sensors and electronic components, which need electric power supply for their proper working. However not all railway lines and vehicles are provided with electric power, furthermore, it can be complex to provide energy to sensors by cables in some location

Active radial technology can effectively improve the curving performance of rail vehicles. The curvature of track is the key parameter of active radial system. In order to acquire this parameter in real time, a new method of curvature measurement based on secondary suspension rotation angle sensing is proposed in this paper. It is proved that this scheme can measure the curvature with small error and

Stability verification of railway wheelsets in Germany can currently become a process difficult to plan. Besides standardised calculations, expensive and often time-consuming test ride measurements have to be conducted. In particular, determining the maximum dynamic torsional stresses resulting from torsional vibration of wheelsets is a frequently discussed topic. Neither an analytical nor an empirical

A DDES based on the SST κ–ω turbulence model was used to simulate the aerodynamic characteristics of a braking plate, and the aerodynamic forces on the plate, the flow structure around the plate and the effect of opening a downstream plate on aerodynamic characteristics of the braking plates were analysed. Some results show that opening the downstream plate significantly decreases both the value and

The transmission system of a motor car directly affects the operating reliability and running safety of a high-speed train. This study examines the coupled torsion vibration responses of a transmission system in a vehicle–track vibration environment. It considers the time-varying mesh stiffness, nonlinear damping characteristics, wheel flexible deformation and wheel–rail interactions. The results are

This paper proposes a linear predictive lateral control method to stabilise a highly automated vehicle (HAV) at the tire-road friction limits when tracking a (tight) desired path. Two approaches are adopted to linearise the vehicle model around the tire saturation region: (1) the lateral force of the front tire is selected as the control input instead of the steer angle and (2) the rear tire dynamics

This paper presents an in-depth analysis of the application of different techniques for vehicle state and tyre force estimation using the same experimental data and vehicle models, except for the tyre models. Four schemes are demonstrated: (i) an Extended Kalman Filter (EKF) scheme using a linear tyre model with stochastically adapted cornering stiffness, (ii) an EKF scheme using a Neural Network (NN)

Railway vehicle dampers undergo degradation and failure after long-term service. Bench tests in this paper indicate a stochastic failure process, in which damping characteristics follow bimodal random distributions between normal and failure; failure probability increases in the ageing process until it becomes deterministic. This failure mode may be neglected due to the probabilistic absence of failure

The gear transmission system is a key part to transmit power for the electrical multiple unit (EMU) and to move the train forward. Its dynamic vibrations affect the operation safety and the dynamic characteristics of the vehicle. Based on the parameters of a certain type of high-speed EMU in China, a rigid-flexible coupling dynamics model of railway vehicle is developed. A flexible gear meshing dynamics