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Tooth Surface design for Variable Transmission Ratio Bevel Gearing

Applied Mathematics 2015年第10期6卷 1685-1695页

作者： Nan Yang Dawei Zhang Yanling Tian School of Mechanical Engineering Tianjin University Tianjin China Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System School of Mechanical Engineering Tianjin University of Technology Tianjin China

A novel CAD method for tooth profile based on the gearing feature has been proposed in this paper, and this method could be applied to the variable transmission ratio and three-dimension situation. The two pitch curves of the two gears can be generated due to the given transmission ratio. The tooth profile curves are formed in each coordinate system of its pitch curve by the gearing process. Finally, the tooth profile could be extracted and translated into a real dimension by CAD method. It is provided a simply thought for tooth profile design to avoid so much complicated mathematical reasoning.

关键词： Computer-Aided design Computational Geometry Gear design Gear Geometry

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Micro-IMU-Based Motion Tracking system for Virtual Training

Micro-IMU-Based Motion Tracking System for Virtual Training

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第三十四届中国控制会议

作者： Yang Zhang Yunfeng Fei Lin Xu Guangyi Sun Institute of Robotics and Automatic Information System Nankai University Tianjin Key Laboratory of Intelligent Robotics Engineering Design and Research Institute of the Second Artillery Corps.

ISBN: (纸本)9781467374439

This paper presents the development of a low cost wireless real-time inertial body tracking system for virtual training. The system is designed to provide highly accurate human body motion capture and interactive three-dimensional(3-D) avatar steering, by combining low cost MEMS inertial measurement units(IMUs), wireless body sensor network(BSN), and Unity 3D virtual reality game engine. First, several wearable MEMS IMU sensors are placed on user's body and limbs according to human skeletal action, and each sensor performs a 9 degrees of freedom(DOF) tracking at a high-speed update rate. Second, a Zigbee-based BSN is designed to support up to 20 MEMS IMU sensor nodes data transmission at 50 Hz sampling frequency. All collected sensors' data are loaded to a Matlab-based PC program by means of serial port. In order to accurately estimate the local orientation of each IMU sensor, an optimized gradient descent algorithm is implemented. The algorithm uses a quaternion representation, which allows accelerometer and magnetometer data to be fused to compute the gyroscope measurement error as a quaternion derivative. Finally, the estimated orientation data by fusion algorithm are imported to a virtual environment, consisting of the 3-D virtual skeletal representation and the virtual scene for specific training. Experimental results indicate that the system achieves < 1o static RMS error and <2o dynamic RMS error. The systems further expand the usability of low cost body tracking solution to virtual training in virtual environments.

关键词： micro inertial measurement unit(IMU) motion capture virtual training gradient descent algorithm wireless sensor network

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Dynamic analysis of a 3-DOF 3-PUU parallel manipulator based on the principle of virtual work

Dynamic analysis of a 3-DOF 3-PUU parallel manipulator based...

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IEEE/ASME (AIM) International Conference on Advanced intelligent Mechatronics

作者： Song Lu Yangmin Li Department of Electromechanical Engineering University of Macau Macao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin China

ISBN: (纸本)9781467391085

This paper presents a straightforward and systematical methodology for conducting the inverse dynamic analysis of a 3-prismatic-universal-universal (PUU) parallel kinematic manipulator (PKM) through employing the principle of virtual work. The proposed 3-PUU PKM possesses three translational degree-of-freedom (DOF). The position, velocity and acceleration of joints are solved via the inverse kinematic analysis, the link Jacobian matrices which map the velocity of the moving platform into the velocity and angular velocity of struts are derived in the fixed coordinate system. Based on the d'Alembert's form of the principle of virtual work, the applied generalized forces of the whole mechanical system are divided into the applied forces of moving platform, struts, sliders, and motor-coupling-leadscrew, respectively. The joint actuated torques are obtained through eliminating the virtual displacement in the dynamic equations. Furthermore, the inertial term, centrifugal and Coriolis term, and gravitational term of the total joint torque are determined. Simulation for a conical spiral trajectory demonstrates that the total torque is dominated by the inertial term.

关键词： Manipulator dynamics Joints Acceleration Dynamics Kinematics Mathematical model

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Closest Distance Searching by GPU-Based Massive Parallel Computation

Closest Distance Searching by GPU-Based Massive Parallel Com...

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IEEE International Conference on Cyber Technology in Automation, Control, and intelligent systems

作者： Yunfeng Fei Yinhao Song Guangyi Sun Engineering Design and Research Institute of the Second Artillery Corps. Nankai University Institute of Robotics and Automatic Information System Tianjin Key Laboratory of Intelligent Robotics

ISBN: (纸本)9781479987313

A simulation system for real-time closest distance searching is developed using GPU-based massive parallel computation technology. The system can be used for minimum distance detection between two three-dimensional (3-D) objects in a virtual environment. First, two 3-D models are converted into vertex/mesh format;then, CUDA-based GPU parallel computation is performed for the nearest neighbor searching, in order to find the closest separation Euler-distance of two objects;at last, Unity3D game engine is used as a testing platform for visualization. Experimental results indicate that the system not only works for arbitrary complex objects (i.e., non-convex object), but also has good real-time capability and high accuracy. Compared with traditional brute force algorithm, our parallel searching is about 50 times faster.

关键词： Closest distance searching Parallel computation GPU Collision detection Virtual reality PARALLEL PROCESSING (COMPUTERS) virtual reality Nearest neighbor query Simulation systems GRAPPER PICK UP Graphics Processing Unit real-time capability Collision detection Collision avoidance

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Optimal design of High Power LED Lamp Heat Dissipation Based on Equivalent Thermal Circuit Method

Optimal Design of High Power LED Lamp Heat Dissipation Based...

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2015 5th International Conference on Computer Sciences and Automation Engineering(ICCSAE 2015)

作者： Feng Liang Lianyu Zhao Youjun Yue Zhuoyin Tong Lizhu Wang School of mechanical engineering Tianjin University of Technology Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System School of automation Tianjin University of Technology

Since the heat dissipation problemis harsh in high power LED lamp, in our studywe suggest an optimal design method of high-power LED lamps radiator based on the equivalent thermal circuit method, we abstract mathematical model of the heat dissipation system of the lamps, then chose several key parameters of radiator--spacing of fins S, height of fins H, thickness of fins t and number of Micro Heat Pipe ArrayN Has design parameters, and set minimum temperature of the chips as optimization objective. Based on the optimization algorithm we have mentioned, we designed a new radiator for high power LED lamps, through steady-heat-thermal analysis in ANSYS software, the junction temperature is far below the requirement. Therefore, the optimization algorithm can be effectively applied to radiator design of high power LED devices with the advantage of accuracy and swiftness.

关键词： optimal design micro heat pipe array high power LED lamp dissipation equivalent thermal circuit method

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design and analysis of a novel 3-D micromanipulator with large range of motion

Design and analysis of a novel 3-D micromanipulator with lar...

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IEEE/ASME (AIM) International Conference on Advanced intelligent Mechatronics

作者： Zhigang Wu Yangmin Li Faculty of Science and Technology University of Macau Taipa Macao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin China

ISBN: (纸本)9781467391085

A novel parallel micromanipulator with large range of motion based on flexible hinges is designed and analyzed in this paper, which has three degrees of freedom motions along x, y and z axes. The Pseudo-Rigid-Body (PRB) model method is applied to obtain the kinetic performance and inputting stiffness. To calculate the natural frequency of the mechanism, the Lagrange method is used to achieve the dynamic and frequency equations. In addition, the working range of the architecture is also calculated, analyzed and compared with other similar structures by using ANSYS software, our designed micromanipulator has larger workspace than other existed stages.

关键词： Mathematical model Micromanipulators Force Fasteners Springs Kinetic energy Computer architecture

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synchronization of coupled reaction-diffusion neural networks with mixed delays

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Complexity 2016年第S2期21卷

作者： Ping He Yangmin Li Department of Electromechanical Engineering Faculty of Science and Technology University of Macau Taipa Macao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin China

The reaction-diffusion neural network is often described by semilinear diffusion partial differential equation (PDE). This article focuses on the asymptotical synchronization and synchronization for coupled reaction-diffusion neural networks with mixed delays (that is, discrete and infinite distributed delays) and Dirichlet boundary condition. First, using the Lyapunov–Krasoviskii functional scheme, the sufficient condition is obtained for the asymptotical synchronization of coupled semilinear diffusion PDEs with mixed time-delays and this condition is represented by linear matrix inequalities (LMIs), which is easy to be solved. Then the robust synchronization is considered in temporal-spatial domain for the coupled semilinear diffusion PDEs with mixed delays and external disturbances. In terms of the technique of completing squares, the sufficient condition is obtained for the robust synchronization. Finally, a numerical example of coupled semilinear diffusion PDEs with mixed time-delays is given to illustrate the correctness of the obtained results. © 2016 Wiley Periodicals, Inc. Complexity 21: 42–53, 2016

关键词： asymptotical synchronization synchronization coupled reaction-diffusion neural networks linear matrix inequality (LMI) partial differential systems (PDSs) mixed delays

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Effects of the pectus excavatum on the spine in patients of pectus excavatum with scoliosis

Effects of the pectus excavatum on the spine in patients of ...

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第十一届全国生物力学学术会议暨第十三届全国生物流变学学术会议

作者： Weihong Zhong Jinduo Ye Jifu Liu Chunqiu Zhang Linwei Lü Chunyue Zhang Bolun Liu Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System Tianjin University of Technology Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems Tianjin University of Technology Military General Hospital of Beijing PLA

Objective:Pectus excavatum(PE)is the most frequently observed congenital deformity of the chest with a deep depression of the sternum in the anterior thoracic *** more than 20%of pectus excavatum patients were reported to have *** to now,no comprehensive analysis about the impact that pectus excavatum has on scoliosis has been performed,although previous research has involved correlation among scoli-

关键词： Effects of the pectus excavatum on the spine in patients of pectus excavatum with scoliosis

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Research of the crack propagation control in a nonlinear rotor

Research of the crack propagation control in a nonlinear rot...

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IEEE International Conference on Mechatronics and Automation

作者： Jun Liu Yong Fan Jianen Chen Xiaofeng Wang Hongbiao Xiang School of Mechanical Engineering Tianjin University of Technology Tianjin China Tianjin key laboratory of the Design and Intelligent control of the Advanced Mechanical system Tianjin University of Technology Tianjin China

ISBN: (纸本)9781479970995

Due to the continuing action of alternating loads, the micro defects of rotor's materials and the micro traumas in the mechanic processing will easily cause the crack propagation and even the catastrophic accidents. The vibration characteristics of the rotor system, the crack breathing states and the crack breathing periods are investigated with different parameters of the synchronous state through the numerical simulation, which are all based on the dynamic model of the nonlinear cracked rotor and the describing function of the breathing crack. The crack breathing states are also studied under the asynchronous state. The paper proposes a novel method of the delaying crack propagation using an Electro-Magnetic Actuator (EMA) in order to realize the vibration control and the delaying crack propagation. By comparing influences of the crack breathing state caused by changes of different parameters (rotational speed, crack angle, crack depth and nonlinear parameters, etc.), the paper summarizes the mutation regulations of the crack breathing state in the synchronous and verifies the feasibility of delaying the crack propagation mechanism. The result of the research shows that the EMA can control the vibration of the nonlinear cracked rotor and delay the crack propagation in the running process of the nonlinear cracked rotor.

关键词： Rotors Vibrations Mathematical model Numerical simulation Numerical models Vibration control Finite element analysis

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Passivity-based synchronization of a new hyperchaotic Lorenz system

Passivity-based synchronization of a new hyperchaotic Lorenz...

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IEEE Conference on Cybernetics and intelligent systems

作者： Ping He Yangmin Li Department of Electromechanical Engineering Avenida da Universidade Taipa Macao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin China

ISBN: (纸本)9781467373395

In this paper, a passivity-based synchronization method is proposed for a new hyperchaotic Lorenz system based on Lyapunov stability theory and linear matrix inequality (LMI) approach. On the basis of the property of the passive system, the passive controller is designed and synchronization of two identical new hyperchaotic Lorenz systems with different initial conditions is realized. Finally, numerical simulations are presented to demonstrate the effectiveness of the proposed chaos control and synchronization schemes.

关键词： Synchronization Control systems Lyapunov methods Complex networks Chaotic communication

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