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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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Gas control technology for coal and gas outburst mines based on new sealing materials

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Geohazard Mechanics 2024年第3期2卷 181-188页

作者： Hongwei Zhang Hongbao Zhao Dongliang Ji Shijie Jing Yuxuan Guo School of Energy and Mining Engineering China University of Mining and Technology(Beijing)Beijing100083China State Key Laboratory of Mechanical Behavior and System Safety of Trafﬁc Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang050043China

In order to solve the problem of gas overlimit in corner corners of coal and gas prominent mines, through thecombination of air leakage mechanism in the goaf, near-ﬁeld ﬁssure expansion and rich area division, blockingmaterial development and optimization, performance measurement of blocking materials and on-site test, westarted to study the causes of gas concentration in corner corners, analysis of roof collapse and transparency incorners and performance test of blocking materials, and optimized the blocking materials by combining laboratory test and engineering test. Considering the thickness of the sealing ﬁlm, the attenuation ratio of the sealingﬁlm thickness, the gelation time, and the gelation viscosity under different ratios, we designed a multi factororthogonal experiment to optimize the optimal ratio suitable for the engineering site. Factors affecting blockingeffectiveness, such as gel water retention and gel ﬂame resistance, were also tested. The sealing scheme wasimplemented in the 2109 working face of a coal and gas outburst mine in Gansu, China. Through on-sitemonitoring of the changes in temperature, gas concentration, and air leakage at each monitoring point beforeand after the use of sealing materials, the analysis of the detection results shows that the temperature changes ateach monitoring point after the use of sealing materials do not exceed 0.2C;The change in oxygen concentrationis less than 0.27 %;The gas concentration has decreased by more than 60 %, with a decrease of 71.32 % in the gasconcentration in the upper corner. The air leakage has decreased by more than 53 %, and the proportion ofdecrease in air leakage at the upper corner is as high as 56.83 %. This air leakage control technology hasremarkable blocking effect, meets the requirements of corner near-ﬁeld ﬁssure blocking material, and is easy toprepare, inexpensive, non-toxic, tasteless and green, providing a successful experience for the treatment of similarcoal and gas outburst min

关键词： Coal and gas outburst Air leakage in goaf Near-ﬁeldﬁssure Gas concentration Air leakage

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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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Periodically stable vibration of homogeneous rod-shaped double pendulum under parametric excitation

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Zhendong yu Chongji/Journal of Vibration and Shock 2020年第16期39卷 231-235页

作者： Zhang, Hongqiao Tian, Ruilan Chen, Enli Guo, Xiuying School of Mechanical Engieering Shijiazhuang Tiedao University Shijiazhuang050043 China State Key Laboratory of Mechanical Behavior in Transfertation Engineering Structure and System Safety Shijiazhuang Tiedao University Shijiazhuang050043 China

Based on the motion of both legs in the walking process of a robot, a homogeneous rod-shaped pendulum motion model under parametric was designed. The motion differential equation of the system was established by the Lagrange method, and its dimensionless treatment was carried out. Nonlinear dynamic analysis of the system with two natural frequencies ratio of 1:3, the relationship curve between length ratio and mass ratio of double pendulum was obtained by theoretical deduction, the mass ratio of two rods could be determined according to the length ratio. On this basis, the differential equation was linearized and decoupled into two Mathieu equations. Finally, the stability interval of the system was determined by the Lindstede-Poincare perturbation method (L-P), and the correctness of the results was verified by numerical simulation with Matlab. © 2020, Editorial Office of Journal of Vibration and Shock. All right reserved.

关键词： Equations of motion

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Wind tunnel tests on aerodynamic characteristics of vehicles on same-storey highway and rail bridge under crosswind

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Journal of Central South University 2022年第8期29卷 2513-2531页

作者： ZOU Yun-feng XUE Fan-rong HE Xu-hui HAN Yan LIU Qing-kuan School of Civil Engineering Central South UniversityChangsha 410075China Hunan Provincial Key Laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering Structure Changsha 410075China School of Civil Engineering and Architecture Changsha University of Science&TechnologyChangsha 410004China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China

In recent years,the safety and comfort of road vehicles driving on bridges under crosswinds have attracted more attention due to frequent occurrences of wind-induced *** study focuses on a container truck and CRH2 high-speed train as research *** tunnel experiments are performed to investigate shielding effects of trains on aerodynamic characteristics of *** results show that aerodynamic interference between trains and trucks varies with positions of trains(upstream,downstream)and trucks(upwind,downwind)and numbers of *** summarize,whether the train is upstream or downstream of tracks has basically no effect on aerodynamic forces,other than moments,of a truck driving on windward sides of bridges(upwind).In contrast,the presence of trains on the bridge deck has a significant impact on aerodynamic characteristics of a truck driving on leeward sides(downwind)at the same *** best shielding effect on lateral forces of trucks occurs when the train is located downstream of ***,the pressure measuring system shows that only lift forces on trains are affected by trucks,while other forces and moments are primarily affected by adjacent trains.

关键词： same-storey highway and rail bridge container truck CRH2 high-speed train aerodynamic characteristics wind tunnel test crosswind

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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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Principal resonance analysis of piecewise nonlinear oscillator with fractional differential

Principal resonance analysis of piecewise nonlinear oscillat...

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第八届国际振动工程会议

作者： Meiqi Wang Wenli Ma Enli Chen Shaopu Yang State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University School of Mechanical Engineering Shijiazhuang Tiedao University

To analyze the piecewise non-linear system with fractional order differential, we introduced fractional order into the two piecewise systems to accurately describe the stress relaxation of viscoelastic materials. We also established a non-linear dynamic model with non-linear stiffness, damping, and fractional order multi-piecewise points. Under periodic excitation,the equation of amplitude frequency relationship of the system was obtained using the average method, and the amplitude frequency response characteristics under different damping, stiffness,and fractional order parameters were provided. The influence of non-linear factors and fractional order terms on the stability of the system was studied. The chaotic behavior of the system under different parameter disturbances was studied, and the results indicate that the system presents chaotic behavior with the change of disturbance parameters. Moreover, the decrease of linear damping will subject the system to a wider range of chaotic state.

关键词： Principal resonance analysis of piecewise nonlinear oscillator with fractional differential

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