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机床与液压 2016年第6期44卷 25-29页

作者： Xiao-xia GUO Tao- tao LI Jia-hai HUANG Long QUAN Sheng-guo WANG Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province Taiyuan University of Technology Taiyuan 030024 China Technology Center of Taiyuan Heavey Machinery Group Yuci Hydraulic Industry Yuci 030600 China

Flow control valve generally consists of constant pressure difference reducing valve and throttle *** it works under the condition of high differential pressure and flow, the pressure loss of reducing valve in-stalled in main loop will get increased and the hydraulic oil temperature will be increased as well. A digital pilotflow control valve is studied in this paper. The main stage is a cartridge valve based on the flow amplifying princi-ple. The pilot stage is digital flow control valve which consists of digital valve and constant pressure difference re-ducing valve. The digital valve controlled by PWM signal has some characteristics such as less throttling loss andgood repeatability. The high pressure loss and hydraulic oil temperature will be effectively reduced by using con-stant pressure difference reducing valve in the small flow pilot circuit. Through theoretical derivation and simula-tion research, the feasibility of this valve is verified, and some conclusions are drawn for the relationships betweenthe performance and structure parameters, which provides theoretical basis for their design.

关键词： Digital flow control valve Pilot control Simulation

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A kind of online self-tuning smith predictor

A kind of online self-tuning smith predictor

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IEEE International Conference on Mechatronics and Automation

作者： Xu Chen Fei Meng Xiaopeng Chen Qiang Huang Intelligent Robotics Institute Beijing Institute of Technology Beijing China Beijing Advanced Innovation Center for Intelligent Robots and System Beijing Institute of Technology Beijing China Key Laboratory of Biomimetic Robots and Systems Beijing Institute of Technology Beijing China International Joint Research Laboratory of Biomimetic Key Laboratory of Intelligent Control and Decision of Comp lex System Beijing China

ISBN: (纸本)9781509023974

This paper presents an online self-tuning Smith Predictor for the First Order Plus Dead Time Model (FOPDT). It can tune time delay through oscillated input and output. Realtime phase difference detection is used to obtain the phase difference between the input and the output. An online tuner is used to minimize the phase difference. Once the phase difference is minimized, the exact time delay is completely compensated. Our method is suitable for both systems with constant time delay or variant time delay.

关键词： Delay effects Temperature control Delays Predictive models Oscillators Robots

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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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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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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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MoS2 heterostructure with tunable phase stability: Strain induced interlayer covalent bond formation

arXiv

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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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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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Analysis of Dynamic Characteristics of Rugged Vessel in the Process of Hepatic Perfusion

Analysis of Dynamic Characteristics of Rugged Vessel in the ...

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IEEE International Conference on Mechatronics and Automation

作者： Songli Wang Jun Liu Yihe Liu Weimin Ge Tianjin key laboratory of the Design and Intelligent Control of the Advanced Mechanical System Tianjin University of Technology BinshuiXidao 391 Tianjin China Tianjin key Laboratory of Organ Transplantation Transplant surgery of Tianjin First Central Hospital Fukang Road 24 Tianjin China

ISBN: (纸本)9781509023974

The paper attempts to analyze the dynamic characteristics in the perfusion process of the hepatic vessel. A model of rugged vessel with a foreign matter was established based upon medical imaging data. The fluid flowing in the rugged vessel was simulated using the perfusion method of the symmetric pulsating flow (SPF) and the steady flow under the bidirectional fluid-structure interaction (FSI). The simulation results, on the one hand, demonstrate the feasibility of SPF within the perfusion process of the rugged vessel in liver. On the other hand, the results clearly show the dynamic behaviors which accorded with actual medical results. Comparing the perfusion results of the rugged vessel using SPF with the steady flow, the difference of vascular deformation is not obvious, while the peak of velocity in the rugged vessel used SPF is about 50% higher than that of the steady flow, that reveals SPF is more likely to take away the foreign matter. The study will be helpful to improve the quality of the donor liver and reduce the influence of subjective factors on the quality of cleaning, and it provides theoretical basis for the liver transplantation.

关键词： Hepatic Perfusion Rugged Vessel Symmetric Pulsating Flow Bidirectional Fluid-Structure Interaction Dynamics

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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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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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