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Nonlinear vibration mechanism of elastic beam in large overall rotation with rotor eccentricity effect

Nonlinear vibration mechanism of elastic beam in large overa...

2021 International Conference on Mechanical Engineering, intelligent Manufacturing and Automation Technology, MEMAT 2021

作者： Zhao, Lei Yan, Zhao-Fang Zhao, Xin-Hua Li, Bin Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System Tianjin China Tianjin China School of Mechanic Engineering Tianjin University of Technology Tianjin China

The eccentric effect of rotor has seriously affected on the stability and precision of the mechanism at high speed for light and flexible mechanism in industrial application. The analysis of nonlinear vibration mechanism must be completed to realize precision and stable control of elastic beam in a large overall rotation. Firstly, the slender flexible rod is assumed as Euler-Bernoulli beam. We apply the deformation theory of elastic beam to establish its kinematic constraint relationship. Its dynamic model is built with Galerkin method and Hamilton principle. Then the Lagrange method is used to establish the rotor dynamics model based on the Jeffcott rotor. The coupling part between the motor and the elastic beam is assumed to be rigidly connected, and the dynamic model of the motor-elastic beam system can be obtained. Lastly, we analyze the nonlinear vibration mechanism of the elastic beam with rotor eccentricity effect through applying the fourth-order Runge-Kutta method and the superposition principle of traveling wave. It provides an important theoretical basis for making an effective vibration suppression strategy for elastic beam. © Published under licence by IOP Publishing Ltd.

关键词： Dynamic models

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intelligent Diagnosis of Planetary Gearboxes based on DAE-CNN 14

Intelligent Diagnosis of Planetary Gearboxes based on DAE-CN...

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14th IEEE Global Reliability and Prognostics and Health Management Conference, PHM-Hangzhou 2023

作者： Kang, Tianbo Zhang, Mian Xie, Ruitong Chen, Jiwei Xiang, Hongbiao Wang, Yuhang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China Tianjin300384 China

ISBN: (纸本)9798350301359

Planetary gearboxes (PGs) are the core transmission components of complex rotating machinery. The diverse forms of internal gear faults often complicate diagnosis and maintenance work. To improve the fault diagnosis accuracy of PGs, this paper proposes a method for diagnosing PG faults based on deep autoencoders (DAE) and convolutional neural networks (CNN). The method fully utilizes the deep learning capability of DAE and combines it with the precise recognition ability of CNN for fault features. Through precise learning in the encoding layer, it achieves deep dimensionality reduction of fault features and further learns these features after dimensionality reduction by CNN. Compared to traditional CNN, the method reduces the computation parameters and resource consumption, resulting in higher precision intelligent fault diagnosis. Experimental results demonstrate that DAE-CNN exhibits stronger fault diagnosis ability than traditional networks. © 2023 IEEE.

关键词： component DAE-CNN deep learning fault diagnosis planetary gearboxes

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Tuning the photocatalytic water-splitting performance with the adjustment of diameter in an armchair WSSe nanotube

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Journal of Energy Chemistry 2021年第10期30卷 228-235,I0007页

作者： Lin Ju Penglan Liu Yifan Yang Liran Shi Gui Yang Li Sun School of Physics and Electric Engineering Anyang Normal UniversityAnyang 455000HenanChina School of Mechanical Medical and Process EngineeringQueensland University of TechnologyGardens Point CampusQLD 4001BrisbaneAustralia School of Electronic and Information Engineering Liaoning Technical UniversityHuludao 125105LiaoningChina Key Lab of Advanced Transducers and Intelligent Control System Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024ShanxiChina

Due to the enigmatical electrostatic potential difference between the inside and outside layers,the relationship between the diameter and the photocatalytic property of the Janus transition metal dichalcogenides nanotube is still *** this job,for the first time we calculate the electrostatic potential difference of the Janus WSSe armchair nanotubes with corresponding building block models through the first principles *** electrostatic potential difference increases as the diameter ***,it is observed that the WSSe armchair nanotubes with smaller diameter have stronger oxidation capacity,weaker reduction capacity,and higher solar-to-hydrogen conversion ***,the diminution of diameter could make the band gap drop,and even cause a direct-indirect transformation of band *** adjustment of diameter could also regulate the ability of adsorbing water molecules at the insider and outside ***,the suitable band edge positions,wide optical absorbance region(to the near-infrared),outstanding solar-to-hydrogen efficiency(up to 28.99%),high carrier separation,adequate photoexcited carrier driving forces,as well as the energetic and thermal stability,render these nanotubes befitting the photocata lytic water-splitting *** study not only predicts a kind of ideal water-splitting photocatalyst,but also shows an effective way to improve their photocatalytic performances.

关键词： Photocatalysis Water-splitting Janus TMD nanotube Density functional theory calculations

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The kinetic characteristics of the clamping unit in injection molding machine driven by new pump control system

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Advances in Information Sciences and Service Sciences 2012年第21期4卷 468-475页

作者： Zhang, Hongjuan Quan, Long Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education Taiyuan University of Technology Taiyuan 030024 Shanxi Province China

In the injection molding machine control system, as the toggle clamping unit has the feature of big rigidity and strong overload, it has been widely used. However the equivalent mass of the clamping unit varies in a very wide range and the intensive instantaneous impact force emerges during the mold closing and opening process, which will cause dynamic performance and control accuracy to difficultly meet the system requirements. In light of this, at first the clamping unit driven by new pump control system is designed. The characteristic and mathematic analysis is done by three-dimensional kinetics modeling and simulating. Then the control strategy of dynamic feed forward compensation and integral separation PID with anti-saturation is put forward to achieve the displacement and velocity synchronization control of the clamping cylinder. The research results are verified by co-simulation. The dynamic performance and control accuracy are improved by adopting the new pump control circuit and the control method.

关键词： Injection molding

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High-accuracy carrier frequency acquisition algorithm of GNSS signal based on numerical approximation method 5

High-accuracy carrier frequency acquisition algorithm of GNS...

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5th International Workshop on advanced Computational Intelligence and intelligent Informatics, IWACIII 2017

作者： Wang, Guangjun Deng, Xuening Wu, Min School of Automation China University of Geosciences Wuhan430074 China China Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex System Wuhan430074 China

The bandwidth of the Doppler frequency shift under high dynamic environment that the GNSS receivers need to search is 5-10 times than the conventional receivers, a large frequency step is generally chosen to improve the satellite signal acquisition speed. Aiming at the problem that acquisition carrier frequency deviation caused by the large step search cannot meet the requirement of the tracking loop design, a fine frequency estimation method based on numerical approximation is proposed in this paper. The proposed method applied the preferred frequency slot and approximated the capture correlation peak combined with the curve fitting method, which can reduce the frequency deviation, and improve the accuracy of acquisition, then simplify the complexity of tracking loop design. Simulation results show that it has higher accuracy than the other two algorithm at different SNR (Signal to Noise Ratio).

关键词： Frequency estimation

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Grain size control in quasi-two-dimensional perovskite thin film via intermediate phase engineering for efficient bound exciton generation

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Science China Materials 2024年第12期67卷 3925-3931页

作者： Guohui Li Wenhui Zhao Kai Lin Kefan Zhao Yujing Wang Aohua Niu Rong Weng Kaibo Zheng Yanxia Cui College of Electronic Information and Optical Engineering Key Laboratory of Interface Science and Engineering in Advanced MaterialsKey Lab of Advanced Transducers and Intelligent Control System of Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China Chemical Physics Division and NanoLund Lund UniversityBox 12422100LundSweden

Quasi-two dimensional(2D)perovskites have emerged as a promising class of materials due to their remarkable photoluminescence efficiency,which stems from their exceptionally high exciton binding *** spatial confinement of excitons within smaller grain sizes could enhance the formation of biexcitons leading to higher radiative recombination ***,the synthesis of high-quality quasi-2D perovskite thin films with controllable grain sizes remains a challenging *** this study,we present a facile method for achieving quasi-2D perovskite thin films with controllable grain sizes ranging from 500 to 900 *** is accomplished by intermediate phase engineering during the film fabrication *** results demonstrate that quasi-2D perovskite films with smaller grain sizes exhibit more efficient bound exciton generation and a reduced stimulated emission threshold down to 15.89µJ cm^(−2).Furthermore,femtosecond transient absorption measurements reveal that the decay time of bound excitons is shorter in quasi-2D perovskites with smaller grain sizes compared to that of those with larger grains at the same pump density,which is 230.5 *** observation suggests a more efficient exciton recombination process in the smaller grain size *** findings would offer a promising approach for the development of efficient bound exciton lasers.

关键词： quasi-2D perovskite intermediate phase engineering bound exciton generation grain size control

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86-Gb/s Optical Chaos Communication over 100-km Fiber Transmission Using Semiconductor Lasers 49

86-Gb/s Optical Chaos Communication over 100-km Fiber Transm...

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49th European Conference on Optical Communications, ECOC 2023

作者： Mao, Xiaoxin Fan, Xiaoqi Wang, Longsheng Fu, Songnian Wang, Yuncai Wang, Anbang Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province Taiyuan030024 China College of Optoelectronics Taiyuan University of Technology Taiyuan030024 China School of Information Engineering Guangdong University of Technology Guangzhou510006 China Guangdong Provincial Key Laboratory of Information Photonics Technology Guangzhou510006 China

An optical-chaos secure communication of 86-Gb/s 16-Ary QAM signal over 100-km fiber transmission is experimentally demonstrated under the 20%-overhead SD-FEC BER threshold of 2.0×10-2 by using wideband chaos syn... 详细信息

ISBN: (纸本)9781839539954

关键词： Semiconductor lasers

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Dynamic modelling and small signal analysis of push-pull bidirectional DC-DC converter

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Computer Modelling and New Technologies 2014年第10期18卷 14-18页

作者： Zhang, Hongjuan Quan, Long Gao, Yan Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education Taiyuan University of Technology Taiyuan China

Bidirectional DC-DC converter can not only act as a contact bridge between two different voltage levels systems, but also can achieve the energy flow in both directions. However, due to the operating characteristics of the active switch and diode in the converter, thereby the inverter becomes a strong nonlinear circuit. In light of this, the push-pull bidirectional DC-DC converter is designed and the method of state space small signal analysis is proposed. First of all, the state-space equations of the converter are established. Then each variable of inverter circuit is averaged in a switching cycle to eliminate the influence of the switching ripple. The respective average variable expressions are decomposed into the DC component and AC small signal component. After the DC component of the signal is eliminated, the expression of the AC small signal component is obtained, to achieve the purpose of separating the small signal. Finally, the expression of small signal component is linearized, thereby the nonlinear system is approximated the DC operating point. This study will provide the theoretical foundation ready for the analysis and design of converter controller.

关键词： Linearization

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Slope-assisted Raman distributed optical fiber sensing

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Photonics Research 2022年第1期10卷 205-213页

作者： JIAN LI XINXIN ZHOU YANG XU LIJUN QIAO JIANZHONG ZHANG MINGJIANG ZHANG College of Physics and Optoelectronics Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Advanced Transducers and Intelligent Control Systems(Ministry of Education and Shanxi Province) Taiyuan University of TechnologyTaiyuan 030024China

Raman distributed optical fiber sensing is required to achieve accurate temperature measurements in a micro-scale *** this study,we first analyze and demonstrate the pulse transmission feature in the temperature variation area and the superposition characteristics of Raman optical time-domain reflectometry(OTDR)signals by numerical *** equations of superimposed Raman anti-Stokes scattered signals at different stages are presented,providing a theoretical basis for the positioning and physical quantity demodulation of whole optical fiber systems based on the OTDR ***,we propose and experimentally demonstrate a slope-assisted sensing principle and scheme in a Raman distributed optical fiber *** the best our knowledge,this is the first experimental demonstration of Raman distributed optical fiber sensing in a centimeter-level spatial measurement region.

关键词： fiber optical OTDR

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Research on the performance of hydraulic excavator with pump and valve combined separate meter in and meter out circuits

Research on the performance of hydraulic excavator with pump...

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International Conference on Fluid Power and Mechatronics (FPM)

作者： Lei Ge Zhixin Dong Weinan Huang Long Quan Jing Yang Wenyong Li Taiyuan University of Technology Key Lab of Advanced Transducers and Intelligent Control System of Ministry of Education Taiyuan China

ISBN: (纸本)9781479987719

Conventional hydraulic actuator is controlled by mechanically connected orifices valve. The controllability of this method is poor and the energy consumption is huge especially under the over-running condition. So a novel system configuration of the hydraulic excavator is presented to improve the problem mentioned above, in which boom cylinder, stick cylinder and swing motor are controlled with separate meter in and meter out technology, bucket cylinder and travel motors are controlled with conventional valves. Firstly, the paper provides a comprehensive review on the development of the separate meter in and meter out technology. Then the principles of load sensing system and SMISMO system applied on the excavator are illustrated though two diagram to show the difference of the two systems. And then a virtual prototype based on the real physical structures is established, which consists of the hydraulic excavator mechanical structure with multi-body dynamics and electro-hydraulic system. The model is verified by the statics and dynamics experiments. Then the dynamic, static performances as well as the energy consumption characteristics of the boom, arm and swing actuators are investigated under the condition of load sensing hydraulic system and the proposed system using the virtual prototype. The control strategy of the actuators is formulated according to their load condition and operation characteristics also based on the detailed analysis. After that, the physical prototype based on the proposed configuration system is established and its performance is tested. The experimental results show that the accuracy of the virtual prototype is validated; the proposed configuration system can significantly decreases the pressure losses through the valve and improve the energy efficiency of the machine; the pressure shocks within hydraulic actuators is decreased as well, thus the stationarity of the whole machine is improved accordingly.

关键词： Valves Actuators Prototypes Energy consumption Cavity resonators Load modeling

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