On the Polygonal Wear Evolution of Heavy-Haul Locomotive Wheels due to Wheel/Rail Flexibility and Its Mitigation Measures

Wheel polygonal wear can immensely worsen wheel/rail interactions and vibration performances of the train and track,and ultimately,lead to the shortening of service life of railway components.At present,wheel/rail medium-or high-frequency frictional interactions are perceived as an essential reason of the high-order polygonal wear of railway wheels,which are potentially resulted by the flexible deformations of the train/track system or other external excitations.In this work,the effect of wheel/rail flexibility on polygonal wear evolution of heavy-haul locomotive wheels is explored with aid of the long-term wheel polygonal wear evolution simulations,in which different flexible modeling of the heavy-haul wheel/rail coupled system is implemented.Further,the mitigation measures for the polygonal wear of heavy-haul locomotive wheels are discussed.The results point out that the evolution of polygonal wear of heavy-haul locomotive wheels can be veritably simulated with consideration of the flexible effect of both wheelset and rails.Execution of mixed-line operation of heavy-haul trains and application of multicut wheel re-profiling can effectively reduce the development of wheel polygonal wear.This research can provide a deep-going understanding of polygonal wear evolution mechanism of heavy-haul locomotive wheels and its mitigation measures.

Research on uninterruptable power supply technology for auxiliary winding of electric locomotive while passing the neutral section

Purpose–Auxiliary power system is an indispensable part of the train;the auxiliary systems of both electric locomotives and EMUs mainly are powered by one of the two ways,which are either from auxiliary windings of traction transformers or from DC-link voltage of traction converters.Powered by DC-link voltage of traction converters,the auxiliary systems were maintained of uninterruptable power supply with energy from electric braking.Meanwhile,powered by traction transformers,the auxiliary systems were always out of power while passing the neutral section of power supply grid and control system is powered by battery at this time.Design/methodology/approach–Uninterrupted power supply of auxiliary power system powered by auxiliary winding of traction transformer was studied.Failure reasons why previous solutions cannot be realized are analyzed.An uninterruptable power supply scheme for the auxiliary systems powered by auxiliary windings of traction transformers is proposed in this paper.The validity of the proposed scheme is verified by simulation and experimental results and on-site operation of an upgraded HXD3C type locomotive.This scheme is attractive for upgrading practical locomotives with the auxiliary systems powered by auxiliary windings of traction transformers.Findings–This scheme regenerates braking power supplied to auxiliary windings of traction transformers while a locomotive runs in the neutral section of the power supply grid.Control objectives of uninterrupted power supply technology are proposed,which are no overvoltage,no overcurrent and uninterrupted power supply.Originality/value–The control strategies of the scheme ensure both overvoltage free and inrush current free when a locomotive enters or leaves the neutral section.Furthermore,this scheme is cost low by employing updated control strategy of software and add both the two current sensors and two connection wires of hardware.

Typical faults and safety analysis of brake controller for AC locomotive

Purpose–The brake controller is a key component of the locomotive brake system.It is essential to study its safety.Design/methodology/approach–This paper summarizes and analyzes typical faults of the brake controller,and proposes four categories of faults:position sensor faults,microswitch faults,mechanical faults and communication faults.Suggestions and methods for improving the safety of the brake controller are also presented.Findings–In this paper,a self-judgment and self-learning dynamic calibration method is proposed,which integrates the linear error of the sensor and the manufacturing and assembly errors of the brake controller to solve the output drift.This paper also proposes a logic for diagnosing and handling microswitch faults.Suggestions are proposed for other faults of brake controller.Originality/value–The methods proposed in this paper can greatly improve the usability of the brake controller and reduce the failure rate.

Canine Myofascial Kinetic Lines: A Descriptive Dissection Study Including Related Function and Locomotion and Comparison of the Human and Equine Myofascial Kinetic Lines

Aim: This dissection study was conducted to verify if the Myofascial kinetic lines, outlined in detail in humans and recently documented in horses, were present in dogs. These dynamic lines present rows of interconnected muscles, myofascia and other fascia structures, which influence the biomechanics of the spine and limbs. Methods: Forty-two dogs of different breeds and genders were dissected, imaged, and videoed. Results: Similar kinetic lines were verified in the dog, as described in humans and horses, and additionally, three new branches of the lines were discovered. The kinetic lines described were three superficial lines: Dorsal, Ventral, and Lateral, which all started in the hindlimb and ended in the temporal and occipital regions. These lines act respectively in spinal extension, flexion, and lateral flexion. Three profound lines, which started in the tail and ended in the head. The Deep Dorsal Line followed the transversospinal myofascia. The Deep Ventral Line showed an additional start deep in the medial hind limb, continued in the hypaxial myofascia, and enveloped all the viscera. Also, the Deep Lateral Line started in the hindlimb but parted along the trunk in the deep lateral myofascial structures. Two helical lines crossed the midline two or three times and served to rotate the spine. The Functional Line established a sling from the axilla to the contralateral stifle and presented a new ipsilateral branch. The Spiral Line connected the head and the ipsilateral tarsus and additionally presented a new straight branch. The four front limb lines describe their motion: the Front Limb Protraction and Retraction, Adduction, and Abduction Lines. Conclusion: The canine lines mirrored the equine and human lines with exceptions due to differences in anatomy, foot posture, lumbosacral flexibility, and their biomechanical constitution as predator versus prey animals. Additionally, three new canine branches were verified and described.

Experimental study and numerical simulation of the impact of under-sleeper pads on the dynamic and static mechanical behavior of heavy-haul railway ballast track

Laying the under-sleeper pad(USP)is one of the effective measures commonly used to delay ballast degradation and reduce maintenance workload.To explore the impact of application of the USP on the dynamic and static mechanical behavior of the ballast track in the heavy-haul railway system,numerical simulation models of the ballast bed with USP and without USP are presented in this paper by using the discrete element method(DEM)-multi-flexible body dynamic(MFBD)coupling analysis method.The ballast bed support stiffness test and dynamic displacement tests were carried out on the actual operation of a heavy-haul railway line to verify the validity of the models.The results show that using the USP results in a 43.01%reduction in the ballast bed support stiffness and achieves a more uniform distribution of track loads on the sleepers.It effectively reduces the load borne by the sleeper directly under the wheel load,with a 7.89%reduction in the pressure on the sleeper.Furthermore,the laying of the USP changes the lateral resistance sharing ratio of the ballast bed,significantly reducing the stress level of the ballast bed under train loads,with an average stress reduction of 42.19 kPa.It also reduces the plastic displacement of ballast particles and lowers the peak value of rotational angular velocity by about 50%to 70%,which is conducive to slowing down ballast bed settlement deformation and reducing maintenance costs.In summary,laying the USP has a potential value in enhancing the stability and extending the lifespan of the ballast bed in heavy-haul railway systems.

An algorithm to remove noise from locomotive bearing vibration signal based on self-adaptive EEMD filter

An improved ensemble empirical mode decomposition(EEMD) algorithm is described in this work, in which the sifting and ensemble number are self-adaptive. In particular, the new algorithm can effectively avoid the mode mixing problem. The algorithm has been validated with a simulation signal and locomotive bearing vibration signal. The results show that the proposed self-adaptive EEMD algorithm has a better filtering performance compared with the conventional EEMD. The filter results further show that the feature of the signal can be distinguished clearly with the proposed algorithm, which implies that the fault characteristics of the locomotive bearing can be detected successfully.

Utility of “loco-check,” self-checklist for “locomotive syndrome” as a tool for estimating the physical dysfunction of elderly people

Aim: A new concept of locomotive syndrome has been proposed by the Japanese Orthopaedic Association. The aim of this study is to clarify the utility of its self-checklist, “loco-check,” as a tool for estimating the physical dysfunction of elderly people. Methods: Subjects were 1124 community-dwelling Japanese people, 557 men and 567 women, aged 40-89 years. Information about the seven “loco-check” items was obtained from present inquiry sheets. Physical functions were examined by grip strength, knee extension strength, walking speed and one-leg standing time with open eyes. The averages of these test values, controlled for age and BMI, were compared between the “loco-check” (+) group and the “loco-check” (-) group. Also we examined about the trend of decline of physical function, together with SF36 physical function subscale score, as the number of the items chosen increased. Results: Adjusted average values of all four physical function examinations in the “lococheck” (+) group were significantly lower than those of the “loco-check” (-) group (all, p . Also the adjusted average values of the majority of four tests were significantly lower in those who checked each of the “loco-check” items than those who did not, for most of the items. It was also revealed that the more items subjects checked, the lower the adjusted average values were, except for one-leg standing time. It was also the case with SF36 physical function subscale score. Conclusion: We showed the utility of “loco-check” as a simple tool not only for noticing the physical dysfunction of elderly people, but also for estimating the extent of it, except for balancing ability, particularly by counting the number of checked items.

An optimization algorithm for locomotive secondary spring load adjustment based on artificial immune

In order to control the locomotive wheel(axle) load distribution, a shimming process to adjust the locomotive secondary spring loads was heretofore developed. An immune dominance clonal selection multi-objective algorithm based on the artificial immune system was presented to further improve the performance of the optimization algorithm for locomotive secondary spring load adjustment, especially to solve the lack of control on the output shim quantity. The algorithm was designed into a two-level optimization structure according to the preferences of the problem, and the priori knowledge of the problem was used as the immune dominance. Experiments on various types of locomotives show that owing to the novel algorithm, the shim quantity is cut down by 30% 60% and the calculation time is about 90% less while the secondary spring load distribution is controlled on the same level as before. The application of this optimization algorithm can significantly improve the availability and efficiency of the secondary spring adjustment process.

A multi-objective train-scheduling optimization model considering locomotive assignment and segment emission constraints for energy saving

Energy saving and emission reduction for railway systems should not only be studied from a technical perspective but should also be focused on management and economics. On the basis of relevant trainscheduling models for train operation management, in this paper we introduce an extended multi-objective trainscheduling optimization model considering locomotive assignment and segment emission constraints for energy saving. The objective of setting up this model is to reduce the energy and emission cost as well as total passenger- time. The decision variables include continuous variables such as train arrival and departure time, and binary vari- ables such as locomotive assignment and segment occu- pancy. The constraints are concerned with train movement, trip time, headway, and segment emission, etc. To obtain a non-dominated satisfactory solution on these objectives, a fuzzy multi-objective optimization algorithm is employed to solve the model. Finally, a numerical example is performed and used to compare the proposed model with the existing model. The results show that the proposed model can reduce the energy consumption, meet exhausts emission demands effectively by optimal locomotive assignment, and its solution methodology is effective.

Dynamic performance of six-axle locomotive subjected to asymmetric brake shoe forces

To research the influence of asymmetric brake shoe forces(ABSF)induced by braking failure on the dynamic performance of six-axle locomotive,the static equilibrium model of three-axle bogie and dynamic model for locomotive are established.The coupling vibration equations of axle hung motor and wheelset are derived.For the air braking,the influence mechanism of ABSF on the wheel-rail asymmetric motion and force characteristics are discussed.It can be found that if the ABSF is applied in the front wheelset,all the wheelsets move laterally in the same direction.Once the ABSF occurs in the middle or rear one,other wheelsets may move laterally towards the opposite direction.The motion amplitude and direction of all wheelsets strictly depend on the resultant moment of suspension yawing moment and brake shoe asymmetric moment.For the asymmetric braking,the free lateral gap of axle-box could increase the wheelset motion amplitude,but could not change the moving direction.In both the straight line and curve,the ABSF may lead to wheelset misaligning motion,intensify the wheel-rail lateral dynamic interaction and deteriorate wheel-rail contact state.Especially for the steering wheelsets,the asymmetric braking increases the wheelset attack angle significantly,which forms the worst braking condition.

Estimation of CO_2 Emissions of Locomotives in China(1975-2005)

Based on annual statistical data collected by the Chinese Railway Statistic Center, the CO2 emissions of locomotives during 1975-2005 were calculated and the emission intensity and its dynamic characteristics were analyzed. The results show that the CO2 emissions of steam locomotives decreased while that of diesel locomotives increased with time, due to the continuous shift from steam to diesel and electric locomotives. The total CO2 emissions of steam and diesel locomo- tives in China decreased from 42.23 Mt in 1975 to 16.40 Mt in 2005. The emission intensity of CO2 from the two kinds of locomotives decreased at an average rate of 2.4 g （converted t kin）-1 per year. The percentage of the CO2 emissions of locomotives to the total CO2 emissions in the sector of transportation, storage and post in China also decreased persistently from 1980 to 2005.

Design and analysis of an electric-locomotive turning system for coal mines

We describe a system for turning the accumulator electric locomotives used in coal mines. This improves transport efficiency and decreases mine construction and production costs. The operating requirements, principles, working features and transmission system are discussed. This system has a simple structure and can be manufactured, transported and assembled easily. It, therefore, can handle accumulator locomotives of middle and small size.

Analysis of positioning of wayside charging stations for hybrid locomotive consists in heavy haul train operations

Hybrid locomotive concepts have been considered as a step towards converting the railway industry into a green transport mode.One of the challenges in integrating a hybrid locomotive in the train consist is that the battery pack in the locomotive needs to be recharged during a long-haul trip which requires stopping of the train.A typical battery pack requires about 1 h to recharge which is unacceptable.With the improvement in the charging system,it is now possible that the same capacity battery pack could be recharged in 10–12 min which can be a competitive option for the railway companies.This paper proposes a method based on simulation to evaluate the positioning of charging stations on a train network.A typical example of a heavy haul train operation hauled by diesel-electric and hybrid locomotives is used to demonstrate the method by using simulation softwares.The result of the simulation study show that the method developed in this paper can be used to evaluate the state of charge(SoC)status of a hybrid locomotive along the track.It is also shown that the SoC status obtained by the simulation method can be further used to assess the positions of charging stations along the track at the design stage.

Nonlinear dynamic fractional sliding mode control to the motor of mining locomotive

The harsh operating environment and complex operating conditions of the mine electric locomotive affect the control performance of the locomotive traction motor.In order to improve the speed control performance of electric locomotive traction motors,a dynamic fractional-order sliding mode control(DFOSMC)algorithm considering uncertain factors was proposed.A load torque sliding mode observer was designed for the complex load disturbance of the traction motor,and its observations were integrated into the DFOSMC controller to overcome the influence of load disturbance.Finally,the stability of the designed controller was proved by Lyapunov's theorem.Besides,the control performance of DFOSMC controller was compared with integer-order sliding mode controller and fractional-order sliding mode controller through simulation experiments.Compared with integer-order sliding mode and fractional-order sliding mode controllers,the dynamic and static performance of the DFOSMC controller with load observation is better,and it has stronger anti-interference ability.The DFOSMC controller effectively improves the control performance of the traction motor of the mining locomotive.

Air Compressor Control System for Energy Saving in Locomotive Service Plant

The actuality and disadvantages of traditional high power asynchronism motor drive air compressor in locomotive ser-vice plant are discussed. In order to reduce the energy consumption and obtain safe running, a variable frequency con-trol method to the motor is supplied. A PLC with touch screen is used for monitoring the status of the compressor and its control system. It also presents energy consumption analysis caused by the variable frequency control method in a locomotive service plant.

Problems,assumptions and solutions in locomotive design,traction and operational studies

Locomotive design is a highly complex task that requires the use of systems engineering that depends upon knowledge from a range of disciplines and is strongly oriented on how to design and manage complex systems that operate under a wide range of different train operational conditions on various types of tracks.Considering that field investigation programs for locomotive operational scenarios involve high costs and cause disruption of train operations on real railway networks and given recent developments in the rollingstock compliance standards in Australia and overseas that allow the assessment of some aspects of rail vehicle behaviour through computer simulations,a great number of multidisciplinary research studies have been performed and these can contribute to further improvement of a locomotive design technique by increasing the amount of computer-based studies.This paper was focused on the presentation of the all-important key components required for locomotive studies,starting from developing a realistic locomotive design model,its validation and further applications for train studies.The integration of all engineering disciplines is achieved by means of advanced simulation approaches that can incorporate existing AC and DC locomotive designs,hybrid locomotive designs,full locomotive traction system models,rail friction processes,the application of simplified and exact wheel-rail contact theories,wheel-rail wear and rolling contact fatigue,train dynamic behaviour and intrain forces,comprehensive track infrastructure details,and the use of co-simulation and parallel computing.The cosimulation and parallel computing approaches that have been implemented on Central Queensland University’s High-Performance Computing cluster for locomotive studies will be presented.The confidence in these approaches is based on specific validation procedures that include a locomotive model acceptance procedure and field test data.The problems and limitations presented in locomotive traction studies in the way they are conducted at the present time are summarised and discussed.

A novel speed sensor-less direct torque control system for mining locomotive haulage

A novel speed sensor-less direct torque control induction motor drive system for the mining locomotive haulage is presented in the paper. Rotor speed identification is based on the model reference adaptive control theory with neural network using back propagation algorithm. The system is implemented using a real-time TMS320F240 digital signal processor. The simulation study and experiment results indicate that the suggested system has good performance.

System integration of China's first PEMFC locomotive

In the face of growing environmental pollution, developing a fuel-cell-driven shunting locomotive is a great challenge in China for environmental protection and energy saving, which combines the environmental advantages of an electric locomotive with the lower infrastructure costs of a diesel-electric locomotive. In this paper, the investigation status and the development trend of the fuel-cell-driven shunting locomotive were introduced. Through innovation of the power system using fuel cells, an experiment prototype of a fuel-cell shunting locomotive was developed, which would reduce the effects on the environment of the existing locomotives. This was the first locomotive to use a proton exchange membrane fuel-cell （PEMFC） power plant in China. From October 2012, we started to test the fuel-cell power plant and further test runs on the test rail-line in Chengdu, Sichuan. The achieved encouraging results can provide fundamental data for the modification of the current individual fuel cell locomotives or further development of the fuel-cell hybrid ones in China.

Discuss about the Driving Device Suspension Mode of Locomotive

分析了机车驱动装置悬挂方式对轮轨在垂向动作用力的影响，介绍机车驱动装置悬挂方式主要结构和技术特点，说明了不同驱动装置悬挂方式在机车的运用。

Lightening Optimization for 200 km/h AC Locomotive Body under Static Strength

机车车体轻量化可以减少列车运行阻力，降低列车牵引功率，提高速度，改善列车的运行品质。近几年我国高速铁路的蓬勃发展，对机车车体轻量化的要求也越来越高。结合大同机车厂200km／h交流传动机车设计项目，在充分调研国内外机车轻量化研究现状的基础上提出了超拉丁方实验设计和可行方向法相结合的组合优化策略，并应用此方法对车体承载结构进行了轻量化优化，随后通过有限元强度分析来验证优化结果。结果证明，与传统方法相比，该方法对于求解类似非线性大型复杂结构的轻量化问题具有求解效率高和求解精度好等优点，具有广泛的应用前景。