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11th World Conference on Titanium, Ti-2007

作者： Shiro, Ayumi Nishida, Masayuki Jing, Tian Advanced Course of Mechanical System engineering Kobe City College of Technology Kobe651-2194 Japan Department of Mechanical engineering Kobe City College of Technology Kobe651-2194 Japan School of Materials Science and Engineering Harbin Institute of Technology Harbin150001 China

ISBN: (纸本)9784889034066

Recently, titanium casting technology attracts attention in the industrial fields. These casting metals are including a various residual stresses due to the heat shrinkage and inclusion particles, et al. In order to apply the casting technology, the accurate estimation of residual stresses is desired in many cases. In this study, it aims at the nondestructive stress evaluation of titanium casting material by the X-ray stress measurement technique. At first in this study, the sin2ψ method which used in the usual X-ray stress measurement was tried to measured the residual stresses. However, it was unsuitable for measurement of titanium casting material because of including coarse grains. After corrosion treatment of the sample surface, the coarse crystal grains are observed on surface, and it could be look by the naked eye. Therefore, another X-ray method for single crystal system was employed to coarse crystal grains, in order to investigate the possibilities of residual stress estimating. Four-axes sample table which can set the both of tilt angle and rotate one on the sample surface was prepared. The stereographic diagrams and the theory of elasticity were used to measure the single crystal stresses on the sample surface. © Ti-2007 - Proceedings of the 11th World Conference on Titanium. All Rights Reserved.

关键词： Residual stresses

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Effects of Wall Emissivity on Aerodynamic Heating in Scramjets

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Fluid Dynamics & Materials Processing 2020年第6期16卷 206-216页

作者： Yue Zhou Pengfei Ju School of Aeronautical Science and Technology Beihang UniversityBeijing100191China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education(Tianjin University of Technology) Tianjin300384China

The effects of the wall emissivity on aerodynamic heating in a scramjet are *** supersonic turbulent combustion flow including radiation is solved in the framework of a decoupled strategy where the flow field is determined first and the radiation field *** particular,a finite difference method is used for solving the flow while a DOM(iscrete ordinates method)approach combined with a WSGGM(weighted sum of gray gases)model is implemented for radiative *** nonreactive turbulent channel flows are examined for a DLR hydrogen fueled scramjet changing parametrically the wall *** results indicate that the wall radiative heating rises greatly with increasing the wall *** the wall emissivity rises,the radiative source and total absorption increase,while the incident radiation decreases ***,although the radiative heating can reach a significant level,its contribution to the total aerodynamic heating is relatively limited.

关键词： Scramjet aerodynamic heating wall emissivity radiation

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Detection of weld defects based on incremental two-dimensional principal component analysis 15

Detection of weld defects based on incremental two-dimension...

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15th IEEE International Conference on Mechatronics and Automation, ICMA 2018

作者： Shen, Yaohua Ge, Weimin Wang, Xiaofeng School of Mechanical Engineering Tianjin University of Technology China Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechanical System Binshui Xidao 391 Xiqing District Tianjin300384 China

ISBN: (纸本)9781538660720

Aiming at the requirements of the real-time detection of weld defects in the industry, the candid covariance-free incremental PCA (CCIPCA) algorithm was introduced into the Two-Dimensional Principal Component Analysis (2PCA) algorithm, therefore an incremental 2DPCA algorithm (I2DPCA) is proposed. Firstly, the images captured by camera are preprocessed to improve the quality of the images because the captured images might be affected in the process of image acquisition. Then the I2DPCA algorithm is used to achieve feature extraction, and the dimension of the images is reduced. Finally, the recognition of weld defects is implemented using the k-nearest neighbor algorithm (KNN). Compared with the methods of traditional recognition by extracting the sizes of several geometric defects, the proposed algorithm has the advantage of the small memory spaces, the high recognition rate and the strong real-time recognition. The experimental results show that the proposed algorithm has higher recognition rate and is more practical than the 2DPCA, and the recognition rate reaches 94%, which can meet the requirements of the real-time detection. © 2018 IEEE.

关键词： Principal component analysis

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A method for optimization design of multiple degrees of freedom micro gyroscope 25

A method for optimization design of multiple degrees of free...

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25th International Congress on Sound and Vibration 2018: Hiroshima Calling, ICSV 2018

作者： Hao, Shuying Song, Yuhao Zhang, Chenqing Feng, Jingjing Zhang, Qichang Tianjin University of Technology School of Mechanical Engineering Tianjin Key Laboratory of Advanced Electromechanical System Design and Intelligent Control National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin China Tianjin University School of Mechanical Engineering Tianjin Key Laboratory of Nonlinear Dynamics and Control Tianjin China

ISBN: (纸本)9781510868458

In order to obtain ideal bandwidth and high sensitivity of multiple degrees of freedom micro gyroscopes, a kind of optimization design method of combining dynamic characteristic extraction with orthogonal experiment is presented in this paper. Firstly, the effect of vibrator mass ratio, structural frequency ratio and damping ratio on dynamic characteristic that is bandwidth and sensitivity of micro gyroscopes was studied, and then the constraint conditions of optimization design was determined according to dynamic characteristic. And on this basis the orthogonal experiment was adopted to set the level range of each factors and optimize sensitivity and bandwidth of the micro gyroscopes by orthogonal table of five factors and four levels. After optimization, the sensitivity of the micro gyroscopes is only slightly increased, but the bandwidth which compares to result of second order sequence optimization is increased by 1590Hz. Therefore, the optimization design method can greatly improve the bandwidth of the micro gyroscopes and be applied to the optimization design of the multiple degrees of freedom micro gyroscopes with wide-bandwidth. © 25th International Congress on Sound and Vibration 2018, ICSV 2018: Hiroshima Calling. All rights reserved.

关键词： Bandwidth

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Study on vibration and crack propagation control of cracked asymmetric rotor based on three-dimensional finite element model 15

Study on vibration and crack propagation control of cracked ...

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15th IEEE International Conference on Mechatronics and Automation, ICMA 2018

作者： Hu, Rong Liu, Jun Chen, Jianen Wang, Xiaofeng Ge, Weimin School of Mechanical Engineering Tianjin University of Technology China Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechanical System Binshui Xidao 391 Xiqing District Tianjin300384 China

ISBN: (纸本)9781538660720

In order to solve the vibration problems of a cracked asymmetric rotor, the three-dimensional finite element model of the rotor is established combined with a nonlinear contact approach. The free interface modal synthesis method is applied to shorten the computation time by reducing the order of the model. The vibration characteristics of the asymmetric rotor and the cracked asymmetric rotor in different crack locations are analyzed by the simulation. The results of numerical simulation show the appearance of crack will affect the resonance frequency and the range of unstable area on the major critical speed. At the same time, the active control of the rotor is realized by the electromagnetic actuator controlled by neural network PID. Secondly, based on the theory of rotor dynamics, the effects of rotational speed and unbalance on the breathing behavior of the cracked rotor are discussed. In this paper, it proposes a novel method delaying the crack extension effectively. In the process of operation, the electromagnetic actuator (EMA) can effectively control the vibration and can delay the crack propagation. © 2018 IEEE.

关键词： Computation theory

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Fuzzy control for omni-directional vehicle with ball wheels

IEEJ Transactions on Electronics, Information and Systems

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IEEJ Transactions on Electronics, Information and systems 2009年第11期129卷 9+2019-2026页

作者： Iida, Kenichi Mori, Taichi Yasuno, Takashi Advanced Mechanical and Control Engineering Course Nara National College of Technology 22 Yata-cho Yamatokooriyama-city Nara 639-1080 Japan Institute of Technology and Science University of Tokushima 2-1 Minamijyosanjima-cyo Tbkushima-city Tokushima 770-8506 Japan

In this paper, motion control for omni-directional vehicle with ball wheels is considered. The proposed omni-directional vehicle has two ball wheels, and the actuators are arranged to X-direction and Y-direction in ball wheel. Hence, omni-directional vehicle has the ability to move in arbitrary speed and direction, and has also the ability to turn around the place. The proposed control system consists of the fixed gain feedback controllers and self tuning fuzzy controllers. To achieve improvement of responses, rules of fuzzy controller are automatically adjusted by a tuning law. To achieve improvement of mobility, the optical mouse sensor is installed on omni-directional vehicle for self-localization. The experimental results demonstrate the effectiveness of the proposed system for improvement of the movement performance of the omni-directional vehicle. © 2009 The Institute of Electrical Engineers of Japan.

关键词： Motion control

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Virtual Models for Operating on Mobile Devices 3

Virtual Models for Operating on Mobile Devices

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3rd International Conference on Mechatronics and Automation Technology, ICMAT 2024

作者： Wang, Xiaofei Xu, Jinyou Xue, Yahong Zhang, Runfeng Hao, Tianze Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology China

ISBN: (纸本)9781643685649

In recent years, the virtual reality technique has been widely used in many fields. One of the most popular applications is for generating virtual models that can be operated on the screen. In the paper, three methods of obtaining virtual models are introduced. One method is by scanning the quick response code. Another method is the use of CADbro software. The third way is to develop an app to help the digital world emerge in real-life scenarios. With the help of virtual technology, ways of teaching, modes of production, and film production are changing. The three methods mentioned in the paper make it easy to generate virtual models for people to operate on mobile devices. Virtual models generated by the three methods can be operated by touching the screen or operating the mouse, whenever and wherever. © 2024 The Authors.

关键词： Virtual environments

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Rational design of chemically complex metallic glasses by hybrid modeling guided machine learning

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npj Computational Materials 2021年第1期7卷 1242-1251页

作者： Z.Q.Zhou Q.F.He X.D.Liu Q.Wang J.H.Luan C.T.Liu Y.Yang Department of Mechanical Engineering College of EngineeringCity University of Hong KongKowloonHong KongChina College of Mechatronics and Control Engineering Shenzhen UniversityShenzhenChina Laboratory for Structures Institute of Materials ScienceShanghai UniversityShanghaiChina Department of Materials Science and Engineering College of EngineeringCity University of Hong KongKowloonHong KongChina Department of Advanced Design and System Engineering College of EngineeringCity University of Hong KongChina

The compositional design of metallic glasses(MGs)is a long-standing issue in materials science and ***,traditional experimental approaches based on empirical rules are time consuming with a low *** this work,we successfully developed a hybrid machine learning(ML)model to address this fundamental issue based on a database containing~5000 different compositions of metallic glasses(either bulk or ribbon)reported since *** the prior works relying on empirical parameters for featurization of data,we designed modeling guided data descriptors in line with the recent theoretical models on amorphization in chemically complex alloys for the development of the hybrid classification-regression ML *** hybrid ML modeling was validated both numerically and *** importantly,it enabled the discovery of MGs(either bulk or ribbon)through the ML-aided deep search of a multitude of quaternary to scenery alloy *** computational framework herein established is expected to accelerate the design of MG compositions and expand their applications by probing the complex and multi-dimensional compositional space that has never been explored before.

关键词： alloy glasses metallic

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Application of PID control based on BP neural network in the expansion machine of organic Rankine cycle system

Application of PID control based on BP neural network in the...

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Geothermal Resources Council 2018 Annual Meeting: Geothermal's Role in Today's Energy Market, GRC 2018

作者： He, Ruijie Wang, Zhigang Fu, Wencheng Tianjin Key Laboratory Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering United States National Demonstration Center Experimental Mechanical and Electrical Engineering Education United States Tianjin University of Technology China

ISBN: (纸本)0934412235

With the rapid development of China's economy, the relative shortage of energy has become one of the important factors restricting economic and social development. At present, the research and development of energy-saving technology in industrial process have important practical significance. The Organic Rankine Cycle (ORC) system is considered to be a technology for the efficient use of low-temperature heat energy, and many researchers have made efforts on the efficiency of ORC system. In this paper, the dynamic performance of the system is adjusted by using the neural network-based PID control method for the expander in the system. Firstly, the control model of the expander in the system is established, and then the control algorithm is applied to the controlled object to make the system run efficiently. The simulation results show that the algorithm has a good control effect compared with the traditional PID control. This control method can effectively improve the efficiency of ORC system. © 2018 International Journal of Caring Sciences. All rights reserved.

关键词： Rankine cycle

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Temperature control Based on Fuzzy Logic Two-degree-of-freedom Smith Internal Model

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Instrumentation 2020年第2期7卷 1-8页

作者： WANG Zhigang HE Meng Tianjin Key Laboratory for Advanced Mechanical System Design and Intelligent Control Tianjin University of TechnologyTianjin 300384China National Demonstration Centre for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin 300384China

According to the characteristics of the large time delay,nonlinearity and the great inertia of temperature control system in biomass pyrolysis reactor,a two-degree-of-freedom Smith internal model controller based on fuzzy control is ***,the mathematical model of the temperature control system is established by using the step response method,and then the two-degree-of-freedom Smith internal model controller is designed,and the good tracking performance and disturbance suppression performance can be obtained by designing the set value tracking controller and interference rejection ***,the fuzzy control algorithm is used to realize the on-line tuning of the control parameters of the two-degree-of-freedom Smith internal model *** simulation results show that,compared with the traditional internal model control,fuzzy internal model PID control and two-degree-of-freedom Smith internal model control,the algorithm proposed in this paper improves the influence of lag time on the control system,realizes the separation control of set point tracking and anti-jamming performance and the self-tuning of control parameters,and improves the control performance of the system.

关键词： Smith Predictive controller Internal Model control Two Degrees of Freedom Fuzzy control Algorithm

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