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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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Low-light traffic Objects Detection for Automated Vehicles 6

Low-light Traffic Objects Detection for Automated Vehicles

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6th CAA International Conference on Vehicular Control and Intelligence, CVCI 2022

作者： Wang, Xuewei Wang, Dongmei Li, Siyuan Li, Shaohua Zeng, Pengtian Liang, Xiao Shijiazhuang Tiedao University State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang China School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang China

ISBN: (数字)9781665453745

ISBN: (纸本)9781665453745

The low-light condition brings huge challenges to the traffic object detection, limiting its application in complex scenarios such as the round-the-clock traffic monitoring and automatic driving. To address this issue, an accurate traffic object detection method in low-light conditions is proposed. First, the dark channel prior knowledge is utilized to restore the scene radiance via the transmission map and the estimation of the atmospheric light. Meanwhile, the grayscale is adjusted by adaptive gamma transformation to further improve the brightness of the image and reduce the impact of low-light conditions. Second, a LL4PH-Net framework equipped with preset anchors and detection branches is developed to detect low-light traffic objects. The performance of the algorithm is tested on the public BDD100K dataset. Experimental results show that compared with the SOTA methods, the proposed LL4PH-Net acquires the best detection mAP, the most lightweight model and a good time efficiency. It can effectively detect traffic objects even under low-light conditions. © 2022 IEEE.

关键词： Image enhancement

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VMD METHOD BASED ON FREQUENCY DOMAIN CORRELATED KURTOSIS AND ITS APPLICATION IN MULTI-FAULT DIAGNOSIS OF WHEELSET BEARING 1

VMD METHOD BASED ON FREQUENCY DOMAIN CORRELATED KURTOSIS AND...

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1st International Conference on mechanical system Dynamics, ICMSD 2022

作者： Li, Cuixing Liu, Yongqiang State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang China School of Traffic and Transportation Shijiazhuang Tiedao University Shijiazhuang China

ISBN: (数字)9781839537837

ISBN: (纸本)9781839537837

Parameter-adaptive VMD method is often used in rolling bearing fault diagnosis. The two key parameters K and D of VMD can be determined adaptively by using an intelligent optimization algorithm. The working environment of wheelset bearing is complex, and the existing parameter-adaptive VMD method is difficult to accurately extract the fault information of wheelset bearing. To solve this problem, a parameter-adaptive VMD method guided by the envelope power spectrum correlated kurtosis is proposed. Correlated kurtosis has strong directivity and is not affected by impact noise and cyclic stationary noise. Meanwhile, at low SNR, the frequency domain correlated kurtosis is more stable than the time-domain correlated kurtosis. Therefore, taking the local maximum envelope power spectrum correlated kurtosis as the objective function, and using the global searching ability of PSO, the optimal parameter combination of VMD can be adaptively determined. VMD is used to analyze the signal, calculate the envelope power spectrum correlated kurtosis of each component, and select the largest one for envelope spectrum analysis. Through simulation and experimental analysis, it is verified that this method can accurately extract the fault characteristics of wheelset bearing under complex interference. © 2022 IET Conference Proceedings. All rights reserved.

关键词： Failure analysis

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Propagation of Rayleigh-type surface waves in a layered piezoelectric nanostructure with surface effects

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Applied Mathematics and Mechanics(English Edition) 2022年第3期43卷 327-340页

作者： Lele ZHANG Jing ZHAO Guoquan NIE Jinxi LIU State Key Laboratory of Mechanical Behavior and System Safety of Tra±c Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China Hebei Key Laboratory of Mechanics of Intelligent Materials and Structures Department of Engineering MechanicsShijiazhuang Tiedao UniversityShijiazhuang 050043China Department of Architecture Shijiazhuang Institute of Railway TechnologyShijiazhuang 050041China

This work investigates the dispersion properties of Rayleigh-type surface waves propagating in a layered piezoelectric nanostructure composed of a piezoelectric nanofilm over an elastic *** one of the most important features of nanostructures,surface effects characterized by surface stresses and surface electric displacements are taken into account through the surface piezoelectricity theory and the nonclassical mechanical and electrical boundary *** expressions of the dispersion equation are derived,and numerical results are provided to examine the effects of several surface-related parameters,including the surface elasticity,surface piezoelectricity,surface dielectricity,surface density,as well as surface residual stress,on the dispersion modes and phase *** size-dependent dispersion behaviors occurring with surface effects are also predicted,and they may vanish once the thickness of the piezoelectric nanofilm reaches a critical value.

关键词： surface effect surface piezoelectricity dispersion behavior piezoelectric nanofilm Rayleigh wave

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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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Numerical analysis of vehicle-bridge coupling vibration concerning nonlinear stress-dependent damping

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Frontiers of Structural and Civil engineering 2022年第2期16卷 239-249页

作者： Pengfei LI Jinquan ZHANG Shengqi MEI Zhenhua DONG Yan MAO Bridge and Tunnel Technology Research Center Research Institute of HighwayMinistry of TransportBeijing100088China National Engineering Laboratory of Bridge Structure Safety Technology Research Institute of HighwayMinistry of TransportBeijing100088China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang050043China School of Civil Engineering Shijiazhuang Tiedao UniversityShijiazhuang050043China

Damping is known to have a considerable influence on the dynamic behavior of *** fixed damping ratios recommended in design codes do not necessarily represent the complicated damping characteristics of bridge *** study investigated the application of stress-dependent damping associated with vehicle-bridge coupling vibration and based on that investigation proposed the stress-dependent damping *** results of the investigation show that the stress-dependent damping ratio is significantly different from the constant damping ratio(5%)defined in the standard *** vehicles travel at speeds of 30,60,and 90,the damping ratios of the bridge model are 3.656%,3.658%,and 3.671%,*** peak accelerations using the regular damping ratio are 18.9%,21.3%,and 14.5%of the stress-dependent damping ratio,*** the vehicle load on the bridge is doubled,the peak acceleration of the mid-span node increases by 5.4 times,and the stress-related damping ratio increases by 2.1%.A corrugated steel-web bridge is being used as a case study,and the vibration response of the bridge is compared with the measured *** acceleration response of the bridge which was calculated using the stress-dependent damping ratio is significantly closer to the measured acceleration response than that using the regular damping ratio.

关键词： vehicle-bridge vibration system dynamic analysis stress-dependent damping energy dissipation

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Multi-Objective Parallel Human-machine Steering Coordination Control Strategy of Intelligent Vehicles Path Tracking Based on Deep Reinforcement Learning

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Chinese Journal of mechanical engineering (English Edition) 2025年第1期38卷 1-19页

作者： Wang, Hongbo Feng, Lizhao Li, Shaohua Chen, Wuwei Zhou, Juntao School of Automotive and Transportation Engineering Hefei University of Technology Hefei230009 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China

In the parallel steering coordination control strategy for path tracking, it is difficult to match the current driver steering model using the fixed parameters with the actual driver, and the designed steering coordination control strategy under a single objective and simple conditions is difficult to adapt to the multi-dimensional state variables’ input. In this paper, we propose a deep reinforcement learning algorithm-based multi-objective parallel human-machine steering coordination strategy for path tracking considering driver misoperation and external disturbance. Firstly, the driver steering mathematical model is constructed based on the driver preview characteristics and steering delay response, and the driver characteristic parameters are fitted after collecting the actual driver driving data. Secondly, considering that the vehicle is susceptible to the influence of external disturbances during the driving process, the Tube MPC (Tube Model Predictive Control) based path tracking steering controller is designed based on the vehicle system dynamics error model. After verifying that the driver steering model meets the driver steering operation characteristics, DQN (Deep Q-network), DDPG (Deep Deterministic Policy Gradient) and TD3 (Twin Delayed Deep Deterministic Policy Gradient) deep reinforcement learning algorithms are utilized to design a multi-objective parallel steering coordination strategy which satisfies the multi-dimensional state variables’ input of the vehicle. Finally, the tracking accuracy, lateral safety, human-machine conflict and driver steering load evaluation index are designed in different driver operation states and different road environments, and the performance of the parallel steering coordination control strategies with different deep reinforcement learning algorithms and fuzzy algorithms are compared by simulations and hardware in the loop experiments. The results show that the parallel steering collaborative strategy based on a deep

关键词： Deep reinforcement learning

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

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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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Influence of vehicle-road coupled vibration on tire adhesion based on nonlinear foundation

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Applied Mathematics and Mechanics(English Edition) 2021年第5期42卷 607-624页

作者： Junning ZHANG Shaopu YANG Shaohua LI Yongjie LU Hu DING School of Traffic and Transportation Shijiazhuang Tiedao UniversityShijiazhuang 050043China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang 050043China Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringShanghai UniversityShanghai 200072China

The influence of pavement vibration on tire adhesion is of great significance to the structure design of vehicle and *** adhesion between tire and road is the key to studying vehicle dynamics,and the precise description of tire adhesion affects the accuracy of dynamic vehicle ***,in most models,only road roughness is considered,and the pavement vibration caused by vehicle-road interaction is *** this paper,a vehicle is simplified as a spring-mass-damper oscillator,and the vehicle-pavement system is modeled as a vehicle moving along an Euler-Bernoulli beam with finite length on a nonlinear *** road roughness is considered as a sine wave,and the shear stress is ignored on the *** to the contact form between tire and road,the LuGre tire model is established to calculate the tire adhesion *** Galerkin method is used to simplify the partial differential equations of beam vibration into finite ordinary differential equations.A product-to-sum formula and a Dirac delt function are used to deal with the nonlinear term caused by the nonlinear foundation,which realizes the fast and accurate calculation of super-high dimensional nonlinear ordinary differential *** addition,the dynamic responses between the coupled system and the traditional uncoupled system are compared with each *** obtained results provide an important theoretical basis for research on the influence of vehicle-road coupled vibration on tire adhesion.

关键词： vehicle system dynamics vehicle-road coupled vibration LuGre tire model Galerkin method

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Design and Wave Propagation Characterization of Starchiral Metamaterials

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Acta Mechanica Solida Sinica 2022年第2期35卷 215-227页

作者： Yajun Xin Han Wang Cong Wang Jinxin Yao Qian Ding Haoqiang Gao Shuliang Cheng Yongtao Sun Key Laboratory of Green Construction and Intelligent Maintenance for Civil Engineering of Hebei Province Yanshan UniversityQinhuangdao 060000China Hebei Province Low-Carbon and Clean Building Heating Technology Innovation Center Yanshan UniversityQinhuangdao 060000China Department of Mechanics and Tianjin Key Laboratory of Nonlinear Dynamics and Control Tianjin UniversityTianjin 300072China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China

Metamaterials with simple artificial topological properties made from industrially produced single-phase materials have extraordinary innovation and *** this paper,we investigated wave propagation characteristics of a hexastarchiral lattice metamaterial with periodic assemblies and used the finite element(FE)method to study the band gap ***,in order to understand the mechanism of band gaps,we discussed the mode shapes of unit cells and found that the bending of the ligament and the overall rotation have a high correlation with the generation of omnidirectional band *** relationships bet ween geometric parameters and band gap properties have also been systematically studied,which demonstrated that the band gaps of the proposed metamaterial could be reasonably predicted through the evolution of geometric ***,the transmission characteristics of finite sandwich panel structures composed of periodic unit cells were calculated to verify the correctness of the band gap simulation results,which proved that the proposed artificial metastructure has potential application value in vibration and noise reduction projects.

关键词： Hexastarchiral lattice metamaterials Band gap properties Finite element method Rotational resonance

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