Hybrid Track Research Articles

Study of tropical cyclone wave characteristics based on a hybrid track clustering method

Study of tropical cyclone wave characteristics based on a hybrid track clustering method

Sustainable solutions for railway using recycled rubber

This paper introduces four innovative applications of waste rubber from scrapped tyres or conveyor belts in railway tracks. They include (a) a synthetic energy-absorbing layer of coalwash, steel furnace slag and rubber crumbs (SFS + CW + RC) for railway subballast, (b) a rubber inter-mixed ballast system (RIBS), (c) energy-absorbing rubber geogrids, and (d) a hybrid track incorporating tyre cells and elements of off-the-road truck tyres. Comprehensive laboratory and field tests have been conducted to investigate the geotechnical properties of these applications. Specifically, an empirical model was developed to predict the permanent deformation response of SFS + CW + RC mixtures that incorporate the effect of granular rubber and axial loads based on cyclic triaxial tests. Large-scale triaxial tests and field trials proved that RIBS exhibited improved energy-absorbing properties, sufficient shear strength and the promising ability to mitigate ballast breakage and stress distribution. A rubber geogrid with an optimal rib thickness of 10.6 mm was selected based on drop-hammer impact tests. The performance of the hybrid track was investigated using the National Testing Facility for High-speed Rail (NTFHR), from which it was found that the reinforced track had significantly less settlement, lateral deformation and ballast breakage than the traditional track.

The role of recycled rubber inclusions on increased confinement in track substructure

Large cyclic and impact loads exerted by heavy haul trains can cause significant deformation and degradation of ballast, leading to poor track geometry and track instability. The application of recycled rubber elements in track substructure to increase confinement of both sub-ballast and shoulder ballast is an innovative solution. In Australia, there is a lack of adequate recycling that leads to large stockpiles of waste tyres. In addition, the reusability of giant off-the-road tyres discarded from mining industry is seriously limited due to their size and weight (over 3.0 m in diameter weighing about 3 tonnes). This study presents a real-size prototype test using the Australia’s first and only National Facility for Cyclic Testing of High-speed Rail to investigate the performance of a hybrid track where tyre-infilled granular waste materials were placed below the ballast layer to replace the traditional capping layer, and arc segments cut from the giant off-the-road tyres were used to confine shoulder ballast. The performance of this hybrid track is compared with an unreinforced track conducted earlier at the same loading conditions. Test results demonstrate that the use of this hybrid system with recycled rubber elements significantly decreases vertical and lateral displacements of ballast and effectively controls the distribution of vertical stress with depth, while reducing vibration and ballast breakage. The outcomes of this study provide a unique solution in a circular economy perspective to strengthen railways to cater for heavier and faster freight trains.

Development of novel track nonlinear energy sinks for seismic performance improvement of offshore wind turbine towers

High-rise and flexible offshore wind turbines (OWTs) are frequently constructed in high-seismicity regions, and passive linear control strategies are commonly adopted to mitigate the seismic responses of OWTs. However, the effectiveness of linear control devices is often sensitive to the frequency contents of seismic motions as well as structural frequencies. Track nonlinear energy sinks (NESs) have recently been proven effective in broadband vibration suppression but also possess amplitude-dependent control performance. Two novel NESs with newly-designed track profiles combining quadratic and quartic polynomials are proposed in the present study to improve the effectiveness of track NESs. One (hybrid track NES) combines nonlinear and linear positive stiffness, whereas the other (bistable track NES) combines nonlinear positive and linear negative stiffness. A statistical linearization technique is adopted to optimize the profiles and damping coefficients of the track NESs. A 3D finite element model of a typical OWT is established, and the restoring force composition of the track NESs is analyzed to simplify their numerical modeling. The effectiveness and robustness of the hybrid and bistable track NESs in OWT vibration control are systematically investigated under a set of synthetic and real ground motions considering different structural frequencies and further compared to the tuned mass damper (TMD) and the traditional track NES with a fourth-order polynomial profile. Numerical results show that hybrid and bistable track NESs outperform their counterpart of the traditional track NES. NESs exhibit a robust behavior against frequency changes despite their slightly less control effectiveness than that of the TMD. Moreover, large response reductions are achieved using the bistable track NES under low and moderate input energy levels.

On the detection-to-track association for online multi-object tracking

Driven by recent advances in object detection with deep neural networks, the tracking-by-detection paradigm has gained increasing prevalence in the research community of multi-object tracking (MOT). It has long been known that appearance information plays an essential role in the detection-to-track association, which lies at the core of the tracking-by-detection paradigm. While most existing works consider the appearance distances between the detections and the tracks, they ignore the statistical information implied by the historical appearance distance records in the tracks, which can be particularly useful when a detection has similar distances with two or more tracks. In this work, we propose a hybrid track association (HTA) algorithm that models the historical appearance distances of a track with an incremental Gaussian mixture model (IGMM) and incorporates the derived statistical information into the calculation of the detection-to-track association cost. Experimental results on three MOT benchmarks confirm that HTA effectively improves the target identification performance with a small compromise to the tracking speed. Additionally, compared to many state-of-the-art trackers, the DeepSORT tracker equipped with HTA achieves better or comparable performance in terms of the balance of tracking quality and speed.

Hybrid rail track quality analysis using nonlinear dimension reduction technique with machine learning

Track geometry parameters from rail track inspection are regulated within unique safety limits for different track classes. This study focuses on developing an index that combines safety and track quality because of the inefficiency of corrective maintenance activities between routine maintenance cycles when federal geometry limits are violated. This combination is achievable by summarizing multivariate track geometry parameters as an improvement to previous linear approaches to address the problem of inefficient track geometry maintenance programs. The use of nonlinear dimension reduction (T-stochastic neighbor embedding (T-SNE)) for hybrid track quality index development and the influence of time-based parameters on track quality is evaluated in this study. The results show that the probability of geometry defects is correlated with principal components, but T-SNE had the best prediction on train-test splits despite its poor performance on a blind validation set. The absence of an observable correlation between the track geometry and acceleration data requires further investigation.

Analyzing the transition from single- to double-track railway lines with nonlinear regression analysis

The demand for freight rail transportation in North America is anticipated to substantially increase in the foreseeable future. Additionally, government agencies seek to increase the speed and frequency of passenger trains operating on certain freight lines, further adding to demand for new railway capacity. The majority of the North American mainline railway network is single track with passing sidings for meets and passes. Expanding the infrastructure by constructing additional track is necessary to maintain network fluidity under increased rail traffic. The additional track can be constructed in phases over time, resulting in hybrid track configurations during the transition from purely single track to a double-track route. To plan this phased approach, there is a need to understand the incremental capacity benefit as a single-track route transitions to a two-main-track route in the context of shared passenger and freight train operations. Consequently, in this study, the Rail Traffic Controller software is used to simulate various hybrid track configurations. The simulations consider different operating conditions to capture the interaction between traffic volume, traffic composition and speed differences between train types. A nonlinear regression model is then developed to quantify the incremental capacity benefit of double-track construction through exponential delay–volume relationships. Adding sections of double track reduces train delay linearly under constant volume. This linear delay reduction yields a convex increase in capacity as double track is installed. These results allow railway practitioners to make more-informed decisions on the optimal strategy for incremental railway capacity upgrades.

하이브리드 궤도회로 태그 인식율 향상에 관한 연구

Track circuit is a simple electrical device which lies in the connection of the two rails by the wheels and axle of locomotives and rolling stock to short out an electrical circuit, used to detect the absence of a train on rail tracks. In railway signaling system, there are similar systems such as RFID and wheel sensor, GPS etc, are research and developing. Hybrid track circuit is using RFID antenna and reader on the cab and RFID tag on the sleeper. because of the safety in railway operation, tag detection of train position detection function in the hybrid track circuit needs high reliability. This paper studied tag recognition enhancement used tag angles.

하이브리드 궤도회로 시험방법 및 절차에 관한 연구

하이브리드 궤도회로 시험방법 및 절차에 관한 연구

하이브리드 궤도회로를 이용한 지하철 정위치정차에 대한 연구

본 논문에서는 하이브리드 궤도회로를 이용한 정위치 정차시스템에 대한 가능성에 대해 연구하였다. 하이브리드 궤도회로는 UHF대역의 RFID시스템을 이용하고 실시간 운영체제를 기반으로 철도차상시스템과의 통신이 가능한 차세대 철도신호시스템의 한 부분이다. 본 논문에서 사용된 UHF대역 RFID 시스템은 원형편파의 태그와 리더 안테나가 사용되고 일체형 리더기는 송신출력 25dBm에서 우수한 인식회수를 얻었다. 현재 수동운행중인 지하철 차량에 이 시스템을 적용하여 정위치 정차를 하게 되면 기존 수동운전에서 기관사의 실수로 역을 지나거나 PSD(Platform Screen Door)와 열차출입문이 Mismatch 되는 현상을 방지할 수 있다. We have studied on the possibility of precise positioning using hybrid Track Circuit system. Hybrid Track Circuit uses RFID which replaces UHF. Hybrid Track Circuit is a part of next generation railroad signal system which is available to communicate with a railway on board system based on a realtime operating system. If applicate on a current hand operating subway, phenomenon caused by driver's mistake such as passing a stop without stopping or mismatch error between PSD and train door should be prevented.

NEAR-INFRARED VARIABILITY IN YOUNG STARS IN CYGNUS OB7

We present the first results from a 124 night J, H, K near-infrared monitoring campaign of the dark cloud L 1003 in Cygnus OB7, an active star-forming region. Using 3 seasons of UKIRT observations spanning 1.5 years, we obtained high-quality photometry on 9,200 stars down to J=17 mag, with photometric uncertainty better than 0.04 mag. On the basis of near-infrared excesses from disks, we identify 30 pre-main sequence stars, including 24 which are newly discovered. We analyze those stars and find the NIR excesses are significantly variable. All 9,200 stars were monitored for photometric variability; among the field star population, about 160 exhibited near-infrared variability (1.7% of the sample). Of the 30 YSOs (young stellar objects), 28 of them (93%) are variable at a significant level. 25 of the 30 YSOs have near-infrared excess consistent with simple disk-plus-star classical T Tauri models. Nine of these (36%) drift in color space over the course of these observations and/or since 2MASS observations such that they cross the boundary defining the NIR excess criteria; effectively, they have a transient near-infrared excess. About half of the YSOs have color-space variations parallel to either the classical T Tauri star locus or a hybrid track which includes the dust reddening trajectory. This indicates that the NIR variability in YSOs that possess accretion disks arises from a combination of variable extinction and changes in the inner accretion disk: either in accretion rate, central hole size and/or the inclination of the inner disk. While some variability may be due to stellar rotation, the level of variability on the individual stars can exceed a magnitude. This is a strong empirical suggestion that protoplanetary disks are quite dynamic and exhibit more complex activity on short timescales than is attributable to rotation alone or captured in static disk models.

Identification of Nuclear Fragments Formed During Fragmentation Reaction with a Heavy-Ion Beam by Using a Hybrid Track Detector System Combining Silver Halide Photographic Film and CR-39 Plastic Track Detectors

Identification of Nuclear Fragments Formed During Fragmentation Reaction with a Heavy-Ion Beam by Using a Hybrid Track Detector System Combining Silver Halide Photographic Film and CR-39 Plastic Track Detectors

Radial fine seek control with fault protection in a digital versatile disc player

The paper proposes a fine seek servo controller for the digital versatile disk (DVD). The proposed control is an integration of a hybrid track position detector, a position accumulator, a position profile generator, a control finite state machine, an estimator, a defect detector, an RFRP signal compensator, a tracking servo equalizer (for both track-following and fine-seek) and a sled servo equalizer. The integration of these blocks enables a wider range of pull-in area for the servo to switch from track seeking to track following. The implementation results show that the proposed control achieves better performance over the conventional velocity control approach. The experimental results also demonstrated the ability of the control to effectively deal with disks with defects or fingerprints.

A novel fine track-seeking scheme for optical storage device

This paper presents a novel hybrid track position (HTP) detector for the track jump controller in an optical disk drive. The servo system then draws the feedback information from the HTP position information instead of the conventional track crossing velocity. The proposed design provides more accurate feedback information, and thus more accurate velocity profile. The experimental results show that the proposed controller achieves better seek time performance. The short jump experiments also show that the proposed system can more effectively cancel the disk eccentricity effect.

The optimality for the distributed Kalman filtering fusion with feedback

A rigorous performance analysis is dedicated to the distributed Kalman filtering fusion with feedback for distributed recursive state estimators of dynamic systems. It is shown that the Kalman filtering track fusion formula with feedback is, like the track fusion without feedback, exactly equivalent to the corresponding centralized Kalman filtering formula. Moreover, the so-called P matrices in the feedback Kalman filtering at both local trackers and fusion center are still the covariance matrices of tracking errors. Although the feedback here cannot improve the performance at the fusion center, the feedback does reduce the covariance of each local tracking error. The above results can be extended to a hybrid track fusion with feedback received by a part of the local trackers.

Oceanic Requirements and Benefits Modeling for Automatic Dependent Surveillance (ADS)

This paper identifies the need to provide timely return-on-investment for new technology. A study conducted by the Boeing Air Traffic Control Systems Analysis group is summarized. The study analyzes requirements and evaluates potential benefits expected from the use of Automatic Dependent Surveillance (ADS) in oceanic operations. The operation of the North Atlantic Oceanic Track System (NAT OTS) was used as the basis for the study.An oceanic tracks separation requirements analysis was performed to investigate the relationship among separation standards, navigation performance, and dependent surveillance. Lateral separations were analyzed using the traditional Reich collision-risk model approach. A longitudinal separation model was developed, based on the use of ADS and with the key parameters of controller intervention rate, tactical control response, and surveillance accuracy.The separation requirements were then used to quantify potential benefits for both the current NAT OTS with reduced separations (assuming all users are ADS equipped) and a postulated hybrid NAT OTS where equipped users derive immediate benefit. Results indicate a substantial savings derived from the hybrid track operation. © 1993 John Wiley & Sons, Inc.