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arXiv 2017年

作者： Ouyang, Bin Xiong, Shiyun Yang, Zhi Jing, Yuhang Wang, Yongjie National Center for Supercomputing Applications University of Illinois at Urbana-Champaign UrbanaIL61801 United States Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow University Suzhou JiangSu215123 China College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan ShanXi030024 China Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province Taiyuan University of Technology Taiyuan ShanXi030024 China Department of Astronautical Science and Mechanics Harbin Institute of Technology Harbin Heilongjiang150001 China Beckman Institute for Advanced Science and Technology University of Illinois at Urbana-Champaign UrbanaIL61801 United States Department of Electrical Engineering and Computer Engineering University of Michigan Ann ArborMI48109 United States

Due to the distinguished properties offered by different structural phases of monolayer MoS2, phase engineering design are urgently required for achieving switchable structural phase. Strain engineering is widely accepted as a clean and flexible method, however, can not be achieved in engineering monolayer MoS2 phase transition because the critical biaxial strain required (~15%) is much larger than measured elastic limit (~11%). In this study, employing density functional theoretical calculations, it has been found out that with the forming of heterostructure between MoS2 with buckled 2D materials such as silicence, germanene and stanene, only a small strain can trigger the phase transition. As being suggested by the constructed phase stability diagram, biaxial deformation as low as 3% in MoS2/silicene and MoS2/stanene sandwich structure, would be sufficient to induce the structural phase transition in MoS2 lattice. This strain falls well within experimental elastic limit, thus would be feasible to realize in experiment. The origin of such behavior can be understood as strain induced interlayer covalent bond formation, which finally make MoS2 lattice more sensitive to external strain. This theoretical work provides one realistic route for achieving flexible phase stabilities in experimental design. Copyright © 2017, The Authors. All rights reserved.

关键词： Molybdenum compounds

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Experimental investigation of a UWB direct chaotic through-wall imaging radar using colpitts oscillator

Experimental investigation of a UWB direct chaotic through-w...

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IET International Radar Conference 2015

作者： Liu, L. Ma, R.X. Xu, H. Wang, W.K. Wang, B.J. Li, J.X. Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education Shanxi Province China Taiyuan University of Technology Taiyuan030024 China

ISBN: (纸本)9781785610387

An ultra-wideband direct chaotic through-wall imaging radar is proposed and experimentally demonstrated. The chaotic signal is generated by an improved Colpitis oscillator. Target range information is achieved by the cross-correlation between the time-delayed reflected echo signal and the replica of the transmitted chaotic signal. Two-dimensional image is obtained by synthetic aperture technology and back projection algorithm. Experimental results of single target and double targets show that the proposed chaotic radar system can through 20cm thick wall to detect and locate the target.

关键词： Computerized tomography

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Maximizing higher derivatives of unknown maps with stochastic extremum seeking

Maximizing higher derivatives of unknown maps with stochasti...

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American control Conference

作者： Greg Mills Miroslav Krstic Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System Tianjin University of Technology Tianjin China College of Computer National University of Defense Technology Changsha China

ISBN: (纸本)9781467386838

We present a stochastic generalization to the scalar Newton-based extremum seeking algorithm which through measurements of an unknown map, maximizes the map's higher derivatives. The proposed method perturbs the estimate of the optimal parameter with the sinusoid of Brownian motion about the boundary of a circle. Then by properly demodulating the map output of the randomly perturbed estimate, the extremum seeking algorithm maximizes the nth derivative only through measurements of the map. The Newton-based extremum seeking approach removes the dependence of the convergence rate on the unknown Hessian of the higher derivative, an effort to improve performance over standard gradient-based extremum seeking. Our design stems from the existing multivariable Newton-based extremum seeking algorithm where a differential Riccati equation estimates the inverse Hessian of the function to be maximized. Algebraically computing a direct estimate of the inverse Hessian is susceptible to singularity, where-as employing the Riccati filter removes that potential. We prove local stability of the algorithm for general nonlinear static maps via stochastic averaging theory developed for extremum seeking.

关键词： Heuristic algorithms Convergence Stability analysis Optimization Demodulation Markov processes Demodulation Heuristic algorithms extremum seeking algorithm Markov chain extremum values Stability analysis Converge maps Riccati equations Hessian RATE DEPENDENCE optimal parameter

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Utilizing Fullerenols as Surfactant for Carbon Nanotubes Dispersions Preparation

Journal of Materials

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Journal of Materials 2017年第1期2017卷

作者： Jianlong Ji Chang Qiao Yali Liu Wendong Zhang Shengbo Sang Xing Yang Aoqun Jian Qianqian Duan Qiang Zhang Ying Liu Micro Nano System Research Center Key Lab of Advanced Transducers and Intelligent Control System of the Ministry of Education College of Information Engineering Taiyuan University of Technology Taiyuan 030024 *** Advanced Coal Mine Machinery and Equipment Collaborative Innovation Center of Shanxi Province College of Information Engineering Taiyuan University of Technology Taiyuan 030024 *** MEMS Laboratory Department of Precision Instruments and Mechanology Tsinghua University Beijing 100084 *** College of Materials Science and Engineering Taiyuan University of Technology Taiyuan 030024 ***

Dispersions of individual carbon nanotubes (CNTs) are crucial for nanodevices and polymer/CNTs nanocomposites. In this paper, stable and homogenous dispersions of individual multiwalled carbon nanotubes (MWCNTs) have been synthesized. The factors influencing the dispersibility mechanism, including the surfactant concentration and the pH value, have been investigated. SEM images display the impurities sticking on MWCNTs which have been removed. The oxygen-containing groups on the surface of MWCNTs sample have been detected through FT-IR and Raman spectra. All experimental results illustrate that using fullerenols as surfactant can greatly improve the dispersibility of MWCNTs. Moreover, the prepared dispersions exhibit good stability that the sediment percentage of fullerenols-MWCNTs is only 5.2% after 5 days.

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On Simulation for Fuzzy control on Oxygen Concentration of the Mixed Air Supplied by Breathing Adjuster 34

On Simulation for Fuzzy Control on Oxygen Concentration of t...

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第三十四届中国控制会议

作者： SUN Hao WANG Shou-jun SUN Qing-lin Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System The College of Mechanical Engineering Tianjin University of Technology The College of Computer and Control Engineering Nankai University Tianjin Key Laboratory of Intelligent Robotics

ISBN: (纸本)9781467374439

The breathing adjuster is the core component of life support system of an aircraft and it is very important to control the valve to make the breathing adjuster supply the pilot the mixed air with the suitable oxygen concentration. In this paper the mathematical model, which describes the relation between the opening degree of the valve of the breathing adjuster and the flight altitude of the aircraft, is set up through analyzing requirement of aviation physiology and working principles of the breathing adjuster. Then a fuzzy controller is designed to control the opening degree of the valve in order to make the breathing adjuster supply to the pilot the mixed air with suitable oxygen concentration. Finally MATLAB Simulink is employed to verify the feasibility and validity of the fuzzy controlling approach. The results of simulating experiments show that the fuzzy control approach proposed in this paper can make the breathing adjuster supply the mixed air with suitable oxygen concentration to the pilot boarded on an aircraft.

关键词： Breathing adjuster,Oxygen concentration,the opening degree of the valve,Fuzzy control,Simulation

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Wire in the Cable-Driven system of Surgical Robot

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IOP Conference Series: Materials Science and Engineering 2017年第1期224卷

作者： X F Wang N Lv H Z Mu L J Xue Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System Tianjin University of Technology School of Mechanical Engineering Tianjin University of Technology School of Mechanical Engineering Zhonghuan Information College Tianjin University of Technology

During the evolution of the surgical robot, cable plays an important role. It translates motion and force precisely from surgeon's hand to the tool's tips. In the paper, the vertical wires, the composition of cable, are mathematically modeled from a geometric point of view. The cable structure and tension are analyzed according to the characteristics of wire screw twist. The structural equations of the wires in different positions are derived for both non-bent cable and bent cable, respectively. The bending moment formula of bent cable is also obtained. This will help researchers find suitable cable and design more matched pulley.

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A Two-Step Fault Diagnosis Framework for Rolling Element Bearings with Imbalanced Data

A Two-Step Fault Diagnosis Framework for Rolling Element Bea...

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2016 13th International Conference on Ubiquitous Robots and Ambient Intelligence (URAI)

作者： Yuan Lan Weiwei Zong Xiaojian Ding Xiaoyan Xiong Xiaohang Han Jiahai Huang Bing Ma Key Laboratory of Ministry of Education in Advance Transducers and Intelligent Control System Institute of Mechatronics Engineering under School of Mechanical EngineeringTaiyuan University of Technology Department of Computer Science Wayne State University Science and Technology on Information Systems Engineering Laboratory The Second Research Institute of China Electronic Technology Group Corporation

Rolling element bearings constitute the key parts on rotating machinery and their fault diagnosis are of great importance. In this paper, a novel Two-Step fault diagnosis framework is proposed to diagnose the status of rolling element bearings with imbalanced data. The Wavelet Packet Transform(WPT) is used to determine the feature vectors. 16-dimensional wavelet packet node energies were extracted from the original datasets as the feature vectors prepared to input to the ***, our proposed framework consists of two steps for the fault diagnosis, where Step One makes use of Weighted Extreme Learning Machine(weighted ELM) in an effort to classify the normal or abnormal categories, and Step Two further diagnoses the underlying anomaly in details. The effectiveness of our proposed approach is testified on the raw data collected from the rolling element bearing experiments conducted in our Institute,and the empirical results showed that our approach is really fast and can achieve the diagnosis accuracies more than 95%.

关键词： Two-Step fault diagnosis framework Weighed ELM ELM Bearing fault diagnosis

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A Two-Step Fault Diagnosis Framework for Rolling Element Bearings with Imbalanced Data

A Two-Step Fault Diagnosis Framework for Rolling Element Bea...

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International Conference on Ubiquitous Robots and Ambient Intelligence

作者： Yuan Lan Weiwei Zong Xiaojian Ding Xiaoyan Xiong Xiaohang Han Jiahai Huang Bing Ma Key Laboratory of Ministry of Education in Advance Transducers and Intelligent Control System Institute of Mechatronics Engineering under School of Mechanical Engineering Taiyuan University of Technology Department of Computer Science Wayne State University Science and Technology on Information Systems Engineering Laboratory The Second Research Institute of China Electronic Technology Group Corporation

ISBN: (纸本)9781509008223

Rolling element bearings constitute the key parts on rotating machinery and their fault diagnosis are of great importance. In this paper, a novel Two-Step fault diagnosis framework is proposed to diagnose the status of rolling element bearings with imbalanced data. The Wavelet Packet Transform (WPT) is used to determine the feature vectors. 16-dimensional wavelet packet node energies were extracted from the original datasets as the feature vectors prepared to input to the classifiers. Next, our proposed framework consists of two steps for the fault diagnosis, where Step One makes use of Weighted Extreme Learning Machine (weighted ELM) in an effort to classify the normal or abnormal categories, and Step Two further diagnoses the underlying anomaly in details. The effectiveness of our proposed approach is testified on the raw data collected from the rolling element bearing experiments conducted in our Institute, and the empirical results showed that our approach is really fast and can achieve the diagnosis accuracies more than 95%.

关键词： Two-Step fault diagnosis framework Weighed ELM ELM Bearing fault diagnosis

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Mobile robot autonomous path planning based on fuzzy logic and filter smoothing in dynamic environment

Mobile robot autonomous path planning based on fuzzy logic a...

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World Congress on intelligent control and Automation (WCICA)

作者： Yupei Yan Yangmin Li University of Macau Taipa Macau MO Dept. of Electromechanical Engineering University of Macau Macao SAR Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin China

ISBN: (纸本)9781467384155

The mobile robot has been one of the hottest fields in recent years, it has been widely applied in the most critical and efficient occasions in the industry, meanwhile, path planning becomes a frontier and interesting research topic for the mobile robot. In this paper, firstly mobile robot is introduced, some universal path planning algorithms of the mobile robot are reviewed, then a fuzzy logic and filter smoothing based on the data from the laser scan sensor is proposed, the path planning and autonomous obstacle avoidance based on this algorithm is emphasized because it can automatically find the best path according to the size and position of gaps between the obstacles in the dynamic environment, finally our designed mobile robot and corresponding Android APP are introduced, the path planning and obstacle avoidance algorithms are tested on this mobile robot, the testing results show this algorithm has the advantage of responding quickly, global optimized and hardware resource saved compared with other algorithms, it is suitable for the mobile robot that is designed on the embedded system and it can meet our designed requirement.

关键词： Mobile robots Heuristic algorithms Path planning Robot sensing systems Algorithm design and analysis Turning Fuzzy logic

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Research on the performance of electro-hydraulic proportional flow valve controlled by pilot pump

Research on the performance of electro-hydraulic proportiona...

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International Conference on Fluid Power and Mechatronics (FPM)

作者： Yunxiao Hao Jiahai Huang Wenyong Li Long Quan Bin Zhao Key Laboratory of Advanced Transducers and Intelligent Control System Taiyuan University of Technology Taiyuan Shanxi China

ISBN: (纸本)9781479987719

Cartridge flow valves, widely applied in heavy machine and equipment, have the advantages of low leakage, large flow capacity, and simple structure. However, in the existence technologies, in order to reduce the influence of load variety on valve flow, a pressure differential compensator or a cartridge type flow sensor should be added to proportional throttle valve. This method reduces valve flow capacity and increases system throttling loss. In large flow occasion, flow only can be indirectly controlled by changing valve opening area for the limitation of the structure. So a low energy consumption, high controllable electro-hydraulic proportional valve which is structured by a hydraulic transistor (Valvistor) and a small displacement hydraulic pump driven by a servo motor is introduced. Based on the Valvistor valve flow amplification principle, main valve flow is controlled by pilot pump flow which is controlled by changing rotation speed without the influence of load variety. In the research, it's known from the analysis of the new principle valve steady flow characteristics that feedback throttle slot pre-opening will cause the decrease of the main valve flow as pressure drop increases. Soa method of pressure differential-pilot pump rotation speed compensation is put forward and it can obtain ideal flow characteristic. Then the dynamic mathematical model is established and the main valve stability criterion is derived. The influence of the valve parameters on main valve performance is analyzed and simulated. The results provide a new method for the large flow electro-hydraulic proportional control system.

关键词： Valves Mathematical model Analytical models Load modeling Force Stability criteria

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