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Optimal Energy-Efficient Operation of a Metro train on a Long and Steep Downhill Segment

CSEE Journal of Power and Energy systems 2023年第6期9卷 2356-2365页

作者： Deqiang He Hanqing Jian Yanjun Chen Jian Miao Zhixiao Luo Chonghui Ren Lang Zhang the department of State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures Guangxi Key Laboratory of Manufacturing System&Advanced Manufacturing TechnologySchool of Mechanical EngineeringGuangxi UniversityNanning 530004China the department of Guangxi Police College Nanning 530028China. the department of Nanning Rail Transit Co. Ltd.Nanning 530029China

Because the standard four-stage operation and con-trol strategy cannot fully utilize the gravitational potential energy of a train operating on a long and steep downhill segment,this paper further improves the method for train operation and control *** improved operation includes three stages of acceleration,coasting-speed limit cruising,and *** the speed limit,time limit,and distance limit as the constraints,the coasting condition switching point,braking condition switching point,traction coefficient,and braking force coefficient are used as the decision ***,an improved train traction energy consumption model is constructed,and an improved differential evolution algorithm is designed to solve this *** improved method is used to simulate two long and steep downhill segments of the Nanning *** results show that the improved method can meet the requirements of speed limit,time limit,and distance *** with the standard four-stage operation,the improved train operation and control strategy can reduce train energy consumption by more than 40%on the two long and steep downhill segments;compared with other similar algorithms,the improved algorithm is more suitable for solving the model.

关键词： Energy-efficient operation improved differential evolution algorithm long and steep downhill segment metro train

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APPLICATION AND DYNAMICS OF MR DAMPER IN THE SECONDARY SUSPENSION system OF HIGH SPEED trainS 1

APPLICATION AND DYNAMICS OF MR DAMPER IN THE SECONDARY SUSPE...

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1st International Conference on mechanical system Dynamics, ICMSD 2022

作者： Zhao, Yiwei Yang, Shaopu Liu, Yongqiang Liao, Yingying Wang, Peng State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang China School of Transportation Shijiazhuang Tiedao University Shijiazhuang China School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang China

ISBN: (数字)9781839537837

ISBN: (纸本)9781839537837

With the increasing of the train speed, the dynamic performance of the train continues to deteriorate. Therefore, how to ensure the dynamic performance of trains including the ride comfort and stability is an important issue for engineers. In this paper, how to ensure the ride comfort of high speed trains is researched. The semi-active control technology of secondary lateral dampers is used to improve the ride comfort of the train. Firstly, a full-scale high speed train model is established by using the Universal Mechanism(UM) software, and the traditional LQR(Linear quadratic regulator) algorithm based on a 9 degrees of freedom(dof) model of high speed trains is used to calculate the active control force. Secondly, the magnetorheological(MR) damper model is used to track the control force through a tracking force controller designed in this paper, and then the MR damping force is fed back to the full-scale vehicle model to form a closed-loop system. Finally, the semi-active simulations is performed. The simulation and comparison results show that the semi-active control based on the LQR method can restrain the lateral vibration of the car body and improve the ride comfort of the train obviously. Although it deteriorates the running safety a little, it is still within the allowable range. © 2022 IET Conference Proceedings. All rights reserved.

关键词： Closed loop systems

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Fault Diagnosis Method for Multiple Sources based on IESFSC-SSRgram

Fault Diagnosis Method for Multiple Sources based on IESFSC-...

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2024 IEEE International Conference on Sensing, Diagnostics, Prognostics, and Control, SDPC 2024

作者： Zhihao, Wu Shixian, Gong Chenguang, Huang Hang, Jin Zechao, Liu Crrc Qingdao Sifang Locomotive and Rolling Stock Co. Ltd National Engineering Laboratory Qingdao China Behavior and System Safety of Traffic Engineering Structure and School of Mechanical Engineering Shijiazhuang Tiedao University State Key Laboratory of Mechanical Shijiazhuang China Data Management Engineering Center Weichai Power Co. Ltd. Weifang China Institute of Magnetic Levitation and Electromagnetic Propulsion China Aerospace Science and Industry Corporation Limited Beijing China Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University State Key Laboratory of Mechanical Shijiazhuang China

ISBN: (纸本)9798350388855

The division and determination of frequency bands are always core problems in fault diagnosis methods for rotating machinery. Currently, the frequency band division strategy of most fault diagnosis methods is the 1/3-binary tree or realized by wavelet packet transform (such as fast kurtosis diagram and Autogram). This method is relatively fixed, making it difficult to accurately cover the resonance frequency band and achieve multi-source fault identification. To address the above problems, an adaptive frequency band division strategy based on Fast Spectral Correlation (FSC) and Scale-Space Representation (SSR) is proposed. The enhanced enveloping spectrum (EES) of each frequency band after division is obtained, and the improved Fault Quantification Index (IFQI) is used to measure the richness of target information in each enveloped spectrum (ES), generating a two-dimensional diagram. The envelope spectrum with the largest IFQI value is selected as the improved envelope spectrum (IES) obtained by the FSC and SSR division strategy (IESFSC-SSRgram), enabling the fault diagnosis of the axle box bearing. The effectiveness and superiority of the proposed method in identifying multi-source concurrent faults in the wheelset bearing system are verified by comparing it with the traditional method. © 2024 IEEE.

关键词： Binary trees

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Research on Brake Failure Control of Heavy Commercial Vehicles Based on Turning Conditions

Research on Brake Failure Control of Heavy Commercial Vehicl...

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Conference on Vehicle Control and Intelligence (CVCI)

作者： Yongjie Lu Fahui Wang Guangfeng Zhang State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang China

ISBN: (数字)9781728184975

ISBN: (纸本)9781728184982

With the rapid rise of the transportation industry, commercial vehicles as an important means of transportation, its safety and stability are paid more and more attention. In order to improve the safety performance of heavy commercial vehicles when braking failure occurs under turning conditions. Based on the vehicle dynamics characteristics, this paper designed the stability control strategy in the case of brake failure in the above conditions, designed a fuzzy PID controller based on yurch angular velocity control, carried out the Trucksim-Simulink joint simulation and hardware in the loop experiment to jointly verify the control effect of the brake. The results show that the influence of vehicle brake failure on vehicle driving stability is reduced, the performance of vehicle brake under long and downhill conditions and turning conditions is improved, and the safety stability of vehicle brake failure in hardware loop is improved, which meets the requirements of national standards for vehicle braking.

关键词： Stability criteria Turning Hardware safety Brakes Acceleration Standards

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A Subdomain Adaptation Based Bearing Fault Diagnosis Method Using Infrared Thermal Images

A Subdomain Adaptation Based Bearing Fault Diagnosis Method ...

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International Conference on Sensing, Diagnostics, Prognostics, and Control (SDPC)

作者： Jie Yao Xiaohui Gu State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang China

ISBN: (数字)9798350388855

ISBN: (纸本)9798350388862

A sub-domain transfer learning method based on multi-scale convolutional neural network and infrared thermal images is proposed to improve the diagnostic accuracy of bearing faults. Firstly, infrared thermal images with more characteristic information are used to represent the healthy condition of bearings instead of vibration signals. Then, a multi-scale convolutional neural network model is constructed to enhance the feature extraction ability, and a sub-domain adaptation method is used to deal with the situation when training and testing samples are not consistent of independent identically distribution. The proposed method is verified by two datasets from rotating machinery and railway bearing test bench. The results show its effectiveness and robustness than some popular peer transfer learning strategies and vibration signal based methods.

关键词： Vibrations Fault diagnosis training Time-frequency analysis Accuracy Transfer learning Feature extraction Convolutional neural networks Spectrogram Testing

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Study of Local Trajectory Planning Based on Fuzzy Dubins Risk Field

Study of Local Trajectory Planning Based on Fuzzy Dubins Ris...

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IEEE International Conference on Industrial Informatics (INDIN)

作者： Shaohua Li Boyu Ma Zekun Yang Xuewei Wang State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang CHN

ISBN: (数字)9798331527471

ISBN: (纸本)9798331527488

A reasonable and safe path is crucial for implementing vehicle active obstacle avoidance which can enhance driving safety and consequently reduce traffic accidents. A risk field that reflects road structures and obstacles is established to address the limitations of traditional algorithms. Additionally, a local planning method incorporating a fuzzy Dubins strategy is proposed. By constructing lane risk fields and obstacle potential fields using exponential functions, a fuzzy controller is developed. This controller adjusts the lane-changing timing and distance based on the environmental and obstacle information obtained from the risk fields. The vehicle trajectory planning under obstacle avoidance conditions is then achieved through Dubins curves. Simulation and experimental results indicate that the proposed local trajectory planning method based on the fuzzy Dubins risk field effectively performs active obstacle avoidance operations under various conditions. It adjusts the lane-changing timing and distance according to the relative position between the vehicle and obstacles at different speeds, demonstrating a good adaptability to different conditions.

关键词： Trajectory planning Roads Wheels Trajectory Timing safety Planning Collision avoidance Informatics Accidents

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Effects of microstructural heterogeneity on fatigue properties of cast aluminum alloys

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Journal of Central South University 2020年第3期27卷 674-697页

作者： JIAO Yi-nan ZHANG Yi-fan MA Shi-qing SANG De-li ZHANG Yang ZHAO Jin-jin WU Sheng-chuan LIU Yong-qiang YANG Shao-pu School of Materials Science and Engineering Hebei Key Laboratory for Mechanics of Intelligent Materials and StructuresShijiazhuang Tiedao UniversityShijiazhuang 050043China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610031China

Cast Al alloys are widely employed for engine components,structural parts,gear box,chassis,*** subjected to mechanical cyclic load during *** accurate fatigue life prediction of these alloys is essential for normal operation as fatigue cracks initiated during operation induce the lubrication oil leak and serious safety *** heterogeneity,including shrinkage/gaspores and secondary phase particles,is the most detrimental factor that affects fatigue life of cast Al *** approximate fatigue life cycles could be estimated based on the size distribution and locations of shrinkage pores/*** relationship between crack population and stress was reported by statistical distributions and the cumulative probability for cast Al alloys fail at a certain stress could be predicted by combination of Paris law and pore size *** depth was found to dominate the stress field around the pore on the surface and the maximum stress increases sharply when the pore intercepted with the surface at its *** microstructure of cast Al alloys usually is composed of primary Al dendrites,eutectic silicon,Fe-rich particles and other intermetallic particles are dependent upon alloy composition and heat *** coalescence of microcracks initiated from the fractured secondary phases was clearly found and can accelerate the initiation and propagation of the fatigue cracks.A link between defect features and the fatigue strength needs to be established through a good understanding of the fatigue damage mechanisms associated with the microstructural features under specific loading *** paper reviews the influences of shrinkage/gaspores and secondary phase particles,formed during casting process,on the fatigue life of Al-Si-Mg cast Al alloys.

关键词： cast aluminum alloys fatigue microstructural heterogeneous shrinkage/gas pore secondary phase particles

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Effect of Relative Phase of Loose Tie Rods on Nonlinear Dynamic behavior of Rod-Fastening Rotor-Bearing-Seal system

SSRN

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SSRN 2024年

作者： Wu, Xianglin Gu, Xiaohui State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China

The circumferential rod-fastening rotor is composed of multiple disks fastened together by preload provided by tie rods evenly distributed along the circumference of rotor. After the rotor has been running for a period of time, some tie rods will loosen and fail to provide preload due to thermal load, centrifugal load, etc. Which causes the preload that was originally evenly distributed in the circumferential direction to become uneven. Uneven preload introduces anisotropy of contact interface stiffness between rotor disks and generalized bending moments, which have important effects on nonlinear dynamic characteristics of rotor-bearing-seal system. Further, it is common for multiple tie rods to become loose at the same time in practical engineering, the relative position of loose tie rods in the circumferential direction will also have an important impact on rotor dynamics. The relevant research has not been done yet. In this paper, a contact model of the rough machined surface is firstly established by combining the statistical contact theory and fractal contact theory, and then the contact stiffness model between disks is established based on the contact model. Finally, the dynamic model of the circumferential rod-fastening rotor-bearing-seal system is established and solved. The effect of relative phase of loose tie rods on the nonlinear dynamic characteristics of rod-fastening rotor-bearing-sealing system is studied. It can be concluded that relative phase of the loose tie rod has an important influence on the frequency, bifurcation, and periodic motion of the rotor system. At lower speed, the anisotropy of contact stiffness caused by loose rods has little effect on the rotor trajectory, while the generalized bending moment has a greater influence on dynamics of the system. At higher speed, the anisotropy of contact stiffness has a great influence on the axis rail of the rod-fastening rotor. © 2024, The Authors. All rights reserved.

关键词： Bending moments

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Simultaneous resonance of Duffing oscillator with fractional-order derivative

Simultaneous resonance of Duffing oscillator with fractional...

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第八届国际振动工程会议

作者： Hang Li Yongjun Shen Department of Mechanical Engineering Shijiazhuang Tiedao University State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University

Duffing-type oscillators can describe many issues in engineering vibration, such as the vertical vibration of pantograph carbon strip suspension system, the response of coupled pitch-roll ship and the nonlinear phenomena of rotor system, and the multiple-term frequency excitation is common case in these issues. For instance, the carbon belt suspension system of pantograph, it is excited by two kinds of harmonic excitations related to the distance between droppers and the span of catenary respectively. In this paper, the simultaneous resonance of fractional-order Duffing oscillator excited by two-term frequency is studied, and the fractional-order term is introduced due to the fact that many materials or devices in engineering exhibit obvious viscoelasticity, which could be accurately described by fractional-order *** approximately analytical solution of the system is obtained by the method of multiple scales, and the amplitude-frequency curve equation and phase-frequency curve equation of the steady-state response are derived from the analytical solution. Furthermore, Lyapunov’s first method is used to quantitatively calculate the stability condition of the steady-state response, based on this, the stability of the simultaneous resonance is analyzed. The effects of nonlinear factor and fractional-order term on the steady-state response is also analyzed by numerical simulation, and the general effects mechanism of the fractional-order term on the mass-spring-damping（MSD） system is revealed, i.e., the equivalent linear stiffness and equivalent linear damping of the fractional-order term are embodied simultaneously in the MSD system, and the focus and intensity of the effects are determined by fractional order and coefficient respectively.

关键词：

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Experimental and calculation of flexuralmechanical properties of reinforced reactive powder concrete simply supported beams

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Gongcheng Lixue/engineering Mechanics 2020年第6期37卷 131-139页

作者： Li, Hai-Yan Zhang, Bo-Yang Li, Jin-Shu State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University ShijiazhuangHebei050043 China Mechanics Engineering Department Shijiazhuang Tiedao University ShijiazhuangHebei050043 China

Reactive powder concrete (RPC) has superior strength, high toughness and excellent durability compared with ordinary concrete (OC). The calculation method of the strength and stiffness of components of RPC is inevitably different from ordinary concrete components. A full-scale test on the bending performance of four reinforced RPC simply supported beams is conducted. The cracking moment, ultimate bending moment and mid-span load-deformation curve of the beam are obtained. The bending deformation characteristics and failure modes of RPC simply supported beams are revealed, and the calculation formulas for the cracking moment and the bending strength of the RPC simply supported beams are derived. The ultimate compressive strain of steel fiber reinforced RPC is 4394 μΕ~5200 μΕ, and the cracking strain is 690 μΕ~820 μΕ, which are much larger than those of OC. Due to the addition of steel fibers, the influence of the tensile stress of the RPC tension zone must be considered. The derived cracking moment, the normal section bending capacity and the calculated value of the stiffness are in good agreement with the experimental values. The calculation formula has high precision and can be used for the design calculation of reinforced RPC beams. © 2020, engineering Mechanics Press. All right reserved.

关键词： Stiffness

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