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Design and kinematic analysis of a novel over constrained parallel manipulator

Paper Asia 2018年第Compendium3期2018卷 87-93页

作者： Zhang, Chao Li, Bin Guo, Peng Zhao, Xinhua Yang, Yuwei Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education [Tianjin University of Technology United States

In this paper, a novel over constrained 2-RRU&RSR parallel manipulator is proposed and analysed. This mechanism is composed of a moving platform and a base, which connected by two identical RRU limbs and one RSR limb. Here, R stand for the revolute, U and S represent universal and spherical joints respectively. Three revolute joints, fixed on the base, are set to be actively actuated. The moving platform of the structure can realize two rotational and one translational freedoms. The design process and kinematic performances are studied in this paper. Firstly, the configuration design and structure characteristics of the mechanism are expounded. Secondly, the number and the properties of degrees of freedom (DOF) of the mechanism are analysed using screw theory. Thirdly, the kinematic problems, including the inverse analyses and the forward position analyses, are solved analytically. Then, the performance of the mechanism, such as reachable workspace, transmission capability, are analysed. Finally, some numerical examples and conclusions of the mechanism are pointed out, and the potential applications of the mechanism are suggested.

关键词： Degrees of freedom (mechanics)

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Structure Design and Analysis of Reconfigurable Fixture Robot Based on the Auto-body Panels

Structure Design and Analysis of Reconfigurable Fixture Robo...

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IEEE International Conference on Mechatronics and Automation

作者： Jilong Li Jun Liu Xiaofeng Wang Weimin Ge School of Mechanical Engineering Tianjin University of Technology Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System Xiqing District Tianjin China Tianjin Key Lab. of the Design & Intell. Control Adv. Mechatronical Syst. Tianjin China

The fixture is an important equipment, and is widely used in the auto-body panels to be assembled and welded. However, most fixtures, which installed on the production lines, are special to make the production cost higher and the production efficiency lower. Therefore, the reconfigurability of the fixture becomes a key factor that effects the production efficiency of automobiles. To handle the above problems, the new reconfigurable fixture robot is proposed in this paper, which can meet the handing, assembling and welding requirements of different automobile's sheet parts on the automobile production lines. First, the three-dimensional model and the kinematic equations of the proposed reconfigurable fixture robot are established. Then, the working space of the reconfigurable fixture robot is also obtained. Finally, the modal analysis of the reconfigurable fixture robot is performed to determine the cause of resonances. Reconfigurable fixture robots are capable of gripping the auto-body panels with the different radii of curvature, which can also meet the work scopes on the production lines.

关键词： Fixtures Manipulators Kinematics Modal analysis Clamps

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A NSGA-II based Peak Load Shifting Optimization Method for Customers with Distributed Generators Considering Time-of-use Price

A NSGA-II based Peak Load Shifting Optimization Method for C...

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Chinese control Conference

作者： Hao Zhou Min Ding Bo Hu Qingyi Wang Zhili Tan Danyun Li Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex System Wuhan P. R. China Global Energy Interconnection Development and Cooperation Organization Beijing P. R. China

With the extensive use of distributed generation, the traditional demand response analysis cannot meet the current requirements. This paper proposes a NSGA-II based peak load shifting optimization method for customers with distributed generators considering time-of-use price. Firstly, a fuzzy classification method divides the daily power into three time segments, peak hours, flat hours and valley hours. Secondly, on the basis of the time-of-use price, a peak load shifting optimization model is built with constraints and the objectives of minimizing the peak load, maximizing the valley load, and minimizing the peak-valley difference. Then, a NSGA-II based optimization method solves the optimal model and obtains the optimal electricity prices of different time segments to shift the peak load and the valley load. Finally, the simulation results shows the effectiveness of the proposed method.

关键词： Load management Load modeling Real-time systems Mathematical model Distributed power generation Optimization Heuristic algorithms

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Study on design method for dynamics of machine tools based on advanced process system

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Paper Asia 2018年第4期COMPENDIUM VOL. 1卷 102-105页

作者： Zhu, Peihao Li, Xiang Lu, KaiJie Zheng, QingChun Liu, JingNa Ma, WenPeng Hu, YaHui Yu, YangBin Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China

Machining accuracy depends not only the manufacturing error, thermal deformation, elastic deformation and wear but also the vibration produced by it. Establishing the dynamics model provides the basis of dynamic analysis. The most common dynamic models of machine tool are finite element model, lumped parameter model, distributed mass model and parameters identification. Above methods are applied by using the methods of multi-body dynamics, finite element and the progress of technology. Design is finite optimization based on dynamic analysis to get limited improvements for existing empirical design. It is not possible to design the machine tool as required to achieve the expected dynamic performance. In order to comply with precision machine tool’s development demand and the challenge of machine structure design, This paper presents physical and dynamic models considering Machine-Tool-Workpiece Process system to discusses the dynamic cutting process of the dynamic cutting load, driving and executing devices under the excitations of non-equilibrium inertial load. The dynamic of machine tool is mapped to the relative displacement of tool nose. © 2018, SHPMedia Sdn Bhd. All rights reserved.

关键词： Dynamic models

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The distributed parameter model of hydraulic axial piston motor and its application in hydraulic excavator swing system

The distributed parameter model of hydraulic axial piston mo...

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作者： Gao, Youshan Huang, Weinan Quan, Long Lan, Yuan Huang, Jiahai Key Laboratory of Advance Transducers and Intelligent Control System Ministry of Education School of Mechanical Engineering Taiyuan University of Technology Taiyuan030024 China School of Mechanical Engineering Taiyuan University of Science and Technology Taiyuan China

Hydraulic axial piston motor is one of the fundamental components in hydraulic systems;it is widely used in engineered machine, especially in high-power drive or reciprocating motion, such as hydraulic excavator. For hydraulic axial piston motor efficient planning, in addition designing and controlling are required for system operating safety and efficiency. Simulation delivers an advantage over analytical approaches and allows better understanding of the motor performance. For multi-piston hydraulic motor, one of the simulation methods, distributed parameter model, could analyze the detailed performance in each piston chamber. Therefore, in this study, we investigate the characteristics of hydraulic axial piston motor by setting up a distributed parameter model based on physical prototype, which includes mechanical-hydraulics coupling process. The effects of the dynamic pressure inside the piston chamber, the fluidic compressibility and other related parameters are considered in the coupling process. At the same time, the distributed parameter model of hydraulic axial piston motor was used in the simulation model of hydraulic excavator. The results indicate that in two-way hydraulic axial piston motor, the valve plane should adopt symmetrical structure, and silencing groove set should be put on both ends of the valve plane slots, which could reduce pressure ripple and overshoot in the piston chamber. Furthermore, the torque characteristics are highly affected by the clearance between the piston and the cylinder bore. Through this research, we may have a better understanding about the mechanism of output torque fluctuation in hydraulic axial piston motor, and the pressure ripple and overshoot in the piston chamber due to through-flow area discontinuity between the silencing groove and the ends of the valve plane slots. The model is verified using a nine-piston hydraulic motor in hydraulic excavator. © Institution of Mechanical Engineers.

关键词： Pistons

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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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Stability and Neimark-Sacker bifurcation analysis for single gene discrete system with delay

Stability and Neimark-Sacker bifurcation analysis for single...

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第37届中国控制会议

作者： Feng Liu Qicheng Mei Fenglan Sun Xinmei Wang Hua O Wang School of Automation China University of Geosciences Hubei key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Research Center of System Theory and Application Chongqing University of Posts and Telecommunications Department of Mechanical Engineering Boston University

The network structure and functional properties of gene regulatory system and their relationships are an important research field in systems *** this paper,a new improved model is proposed based on the study of gene expression *** model takes into account the effect of protein concentration on the gene expression,so as to obtain a new bifurcation point and improve the performance of the *** validity of the model is verified by theoretical analysis and data simulation.

关键词： Stability Neimark-Sacker bifurcation single gene discrete system delay

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Flexible pulses from carbon nanotubes mode-locked fiber laser

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Chinese Physics B 2016年第12期25卷 258-261页

作者：杨玲珍杨义王娟芬 College of Physics and Optoelectronics Taiyuan University of Technology Laboratory of Advanced Transducers and Intelligent Control System Ministry of EducationTaiyuan University of Technology

We demonstrate a flexible erbium-doped pulsed fiber laser which achieves the wavelength and pulse width tuning by adjusting an intracavity filter. The intracavity filter is flexible to achieve any of the different wavelengths and bandwidths in the tuning range. The wavelength and width of pulse can be tuned in a range of - 20 nm and from - 0.8 ps to 87 ps, respectively. The flexible pulsed fiber laser can be accurately controlled, which is insensitive to environmental disturbance.

关键词： fiber laser mode-locked laser wavelength and pulse width tunable carbon nanotubes

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Enhancing squeezing and nonclassicality of light in atom-optomechanical systems

arXiv

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arXiv 2018年

作者： Guo, Yanqiang Guo, Xiaomin Li, Pu Shen, Heng Zhang, Jing Zhang, Tiancai Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education Taiyuan University of Technology Taiyuan030024 China Institute of Optoelectronic Engineering College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan030024 China State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-Electronics Shanxi University Taiyuan030006 China Clarendon Laboratory University of Oxford Parks Road OxfordOX1 3PU United Kingdom

Quadrature squeezing of light is investigated in a hybrid atom-optomechanical system comprising a cloud of two-level atoms and a movable mirror mediated by a single-mode cavity field. When the system is at high temperatures with quadrature fluctuations of light much above the standard quantum limit (SQL), excitation counting on the collective atomic state can effectively reduce the light noise close to the SQL. When the system is at low temperatures, considerable squeezing of light below the SQL is found at steady state. The squeezing is enhanced by simply increasing the atom-light coupling strength with the laser power optimized close to the unstable regime, and further noise reduction is achieved by decreasing various losses in the system. The presence of atoms and excitation counting on the atoms lessen the limitation of thermal noise, and the squeezing can be achieved at environment temperature of the order K. The nonclassicality of the light, embodied by the negative distributions of the Wigner function, is also studied by making non-Gaussian measurements on the atoms. It is shown that with feasible parameters excitation counting on the atoms is effective in inducing strongly optical nonclassicality. Copyright © 2018, The Authors. All rights reserved.

关键词： Atoms

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Fabrication of ordered micro- and nano-scale patterns based on optical discs and nanoimprint

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Optoelectronics Letters 2016年第4期12卷 241-244页

作者：郭慧晶张校亮李晓春 Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi ProvinceColleges of Physics and Optoelectronics Taiyuan University of Technology

A simple method to fabricate one-dimensional(1-D) and two-dimensional(2-D) ordered micro- and nano-scale patterns is developed based on the original masters from optical discs, using nanoimprint technology and soft stamps. Polydimethylsiloxane(PDMS) was used to replicate the negative image of the 1-D grating pattern on the masters of CD-R, DVD-R and BD-R optical discs, respectively, and then the 1-D pattern on one of the PDMS stamps was transferred to a blank polycarbonate(PC) substrate by nanoimprint. The 2-D ordered patterns were fabricated by the second imprinting using another PDMS stamp. Different 2-D periodic patterns were obtained depending on the PDMS stamps and the angle between the two times of imprints. This method may provide a way for the fabrication of complex 2-D patterns using simple 1-D masters.

关键词： Compact disks Fabrication Microchannels Nanotechnology Optical data storage Optical disk storage Polydimethylsiloxane Silicones

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