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Automatic calibration method of voxel size for cone-beam 3D-CT scanning system

Chinese Physics C 2014年第4期38卷 69-74页

作者：杨民王晓龙刘义鹏孟凡勇李兴东刘文丽魏东波 School of Mechanical Engineering and Automation Beijing Univ.of Aeronautics and Astronautics Department of Control Science and Engineering Harbin Institute of Technology State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of Sciences National Institute of Metrology

For a cone-beam three-dimensional computed tomography （3D-CT） scanning system, voxel size is an important indicator to guarantee the accuracy of data analysis and feature measurement based on 3D-CT images. Meanwhile, the voxel size changes with the movement of the rotary stage along X-ray direction. In order to realize the automatic calibration of the voxel size, a new and easily-implemented method is proposed. According to this method, several projections of a spherical phantom are captured at different imaging positions and the corresponding voxel size values are calculated by non-linear least-square fitting. Through these interpolation values, a linear equation is obtained that reflects the relationship between the voxel size and the rotary stage translation distance from its nominal zero position. Finally, the linear equation is imported into the calibration module of the 3D-CT scanning system. When the rotary stage is moving along X-ray direction, the accurate value of the voxel size is dynamically exported. The experimental results prove that this method meets the requirements of the actual CT scanning system, and has virtues of easy implementation and high accuracy.

关键词： cone-beam CT voxel size least square fitting automatic calibration

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Hovering control of a Nano Quadrotor Unmanned Aerial Vehicle Using Optical Flow 33

Hovering Control of a Nano Quadrotor Unmanned Aerial Vehicle...

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第三十三届中国控制会议

作者： XIAN Bin LIU Yang ZHANG Xu CAO Meihui Wang Fu The Institute of Robotics and Autonomous System the Tianjin Key Laboratory of Process Measurement and ControlSchool of Electrical Engineering and AutomationTianjin University

ISBN: (纸本)9781479947249

In this paper, a PD controller which uses optical flow to obtain position and velocity feedback is proposed for the autonomous hovering flight control of a nano quadrotor unmanned aerial vehicle(UAV). The nano quadrotor UAV has a mass less than 100 g and is comparatively much smaller than the micro vehicles utilized in previous research. Due to the limited size and payload ability, a wireless camera is employed as the onboard visual device to obtain the position and translational velocity of the UAV. Experiment results are included to demonstrate the good control performance of the proposed design.

关键词： Nano Quadrotor UAV,Optical Flow,Autonomous control

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Motion comparison method combining segmented multi-Joint line graphs with the SIFT matching technique

Motion comparison method combining segmented multi-Joint lin...

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4th International Conference on Frontiers of Manufacturing Science and Measuring Technology, ICFMM 2014

作者： Zeng, Ming Ren, Hong Lin Meng, Qing Hao Chen, Chang Wei Ma, Shu Gen Tianjin Key Laboratory of Process Measurement and Control Institute of Robotics and Autonomous Systems School of Electrical Engineering and Automation Tianjin University Tianjin 300072 China

ISBN: (纸本)9783038351924

In this paper, an effective motion comparison method based on segmented multi-joint line graphs combined with the SIFT feature matching method is proposed. Firstly, the multi-joint 3D motion data are captured using the Kinect. Secondly, 3D motion data are normalized and distortion data are removed. Therefore, a 2D line graph can be obtained. Next, SIFT features of the 2D motion line graph are extracted. Finally, the line graphs are divided into several regions and then the comparison results can be calculated based on SIFT matching ratios between the tutor's local line graph and the trainee's local line graph. The experimental results show that the proposed method not only can easily deal with the several challenge problems in motion analysis, e.g., the problem of different rhythm of motions, the problem of a large amount of data, but also can provide detailed error correction cues. © (2014) Trans Tech Publications, Switzerland.

关键词： Motion analysis

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Recurrence characteristics analysis of near-Surface wind speed signal with different sampling frequencies

Recurrence characteristics analysis of near-Surface wind spe...

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4th International Conference on Frontiers of Manufacturing Science and Measuring Technology, ICFMM 2014

作者： Zeng, Ming Wu, Zhan Xie Meng, Qing Hao Li, Jing Hai Ma, Shu Gen Tianjin Key Laboratory of Process Measurement and Control Institute of Robotics and Autonomous Systems School of Electrical Engineering and Automation Tianjin University Tianjin 300072 China

ISBN: (纸本)9783038351924

The wind is the main factor to influence the propagation of gas in the atmosphere. Therefore, the wind signal obtained by anemometer will provide us valuable clues for searching gas leakage sources. In this paper, the Recurrence Plot (RP) and Recurrence Quantification Analysis (RQA) are applied to analyze the influence of recurrence characteristics of the wind speed time series under the condition of the same place, the same time period and with the sampling frequency of 1hz, 2hz, 4.2hz, 5hz, 8.3hz, 12.5hz and 16.7hz respectively. Research results show that when the sampling frequency is higher than 5hz, the trends of recurrence nature of different groups are basically unchanged. However, when the sampling frequency is set below 5hz, the original trend of recurrence nature is destroyed, because the recurrence characteristic curves obtained using different sampling frequencies appear cross or overlapping phenomena. The above results indicate that the anemometer will not be able to fully capture the detailed information in wind field when its sampling frequency is lower than 5hz. The recurrence characteristics analysis of the wind speed signals provides an important basis for the optimal selection of anemometer. © (2014) Trans Tech Publications, Switzerland.

关键词： Time series

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Biomechanical analysis of typical upper limb movements based on Kinect-LifeMOD

Biomechanical analysis of typical upper limb movements based...

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4th International Conference on Frontiers of Manufacturing Science and Measuring Technology, ICFMM 2014

作者： Zeng, Ming Chen, Chang Wei Meng, Qing Hao Ren, Hong Lin Ma, Shu Gen Tianjin Key Laboratory of Process Measurement and Control Institute of Robotics and Autonomous Systems School of Electrical Engineering and Automation Tianjin University Tianjin 300072 China

ISBN: (纸本)9783038351924

In traditional biomechanical analysis of upper limb, the high-precision motion data and lifelike human models are needed. It is obvious that those processes are costly and time-consuming. In this paper, a novel and simple combination method based on Kinect-LifeMOD is proposed. Firstly, the Microsoft Kinect (a latest depth sensor) is used to build a cheap and precise motion capture platform. Real-time and reliable key-node rotation data of human skeletons can be acquired by this motion capture system. Next, rotation data is converted into position data as the input of the LifeMOD software which can establish mathematical model of upper limb and execute biomechanical analysis automatically. The experimental results show that the proposed method could achieve the satisfactory performance. © (2014) Trans Tech Publications, Switzerland.

关键词： Biomechanics

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Online Identification of Multivariable Nonlinear processes with Iterative Structure Learning and Application to a Diesel Engine

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IFAC Proceedings Volumes 2014年第3期47卷 9216-9222页

作者： Marek Kowalczyk Boliang Yi Rolf Isermann Institute of Automatic Control and Mechatronics Laboratory of Control Engineering and Process Automation Technical University Darmstadt Germany

This contribution presents a new methodology for the online identification, which allows the modeling of the stationary and dynamic behavior of nonlinear combustion engines with many input and output variables in short time with an appropriate model structure. The used models are local polynomial model trees. The necessary enhancements and adaptations of the identification algorithm for local polynomial model trees for the online methodology are presented. To enable an online identification, not only the parameters but also the structure of the models has to be adapted to the ongoing measuring procedure at a test bench. This structure adaptation methods use iteratively recorded measured data for the determination of an optimized model partition and regressor selection regarding the quality and complexity of the model. This maximizes the iterative improvement of the mathematical model, leading to a reduced test bench time. The applicability of the developed methodology is shown for the identification of a model from both, an artificial test function as well as a real diesel engine.

关键词： Engine modeling Mechatronic combustion engine Iterative measurements Identification methods Online identification Model structure adaptation

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control of a continuous stirred tank reactor using advanced approaches 21

Control of a continuous stirred tank reactor using advanced ...

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21st International Congress of Chemical and process engineering, CHISA 2014 and 17th Conference on process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction, PRES 2014

作者： Závacká, J. Vasičkaninová, A. Bakošová, M. Department of Information Engineering and Process Control Institute of Information Engineering Automation and Mathematics Faculty of Chemical and Food Technology Slovak University of Technology in Bratislava Radlinského 9 Bratislava812 37 Slovakia

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Consensus control and feedback graph co-design for MIMO discrete-time multi-agent systems

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Journal of control and Decision 2014年第1期1卷 18-33页

作者： Guoxiang Gu Fei Liu Xiang Chen Department of Electrical and Computer Engineering Louisiana State UniversityBaton RougeLAUSA Key Laboratory of Advanced Process Control for Light Industry(Ministry of Education)China Institute of AutomationJiangnan UnniversityWuxiP.R.China Department of Electrical and Computer Engineering University of WindsorWindsorCanada

This paper studies consensus control for multi-input/multi-output(MIMO)discrete-time multi-agent systems(MASs).It makes use of the novel idea of resource allocation in designing both the communication graph and feedback *** weakest consensusability condition is obtained for MASs over both directed and undirected graphs,which extends the existing results to MIMO discrete-time *** synthesis procedures are also *** work demonstrates the importance of the graph and controller co-design based on resource allocation for MIMO discrete-time MASs.

关键词： consensus control gain margin multi-agent systems

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Implementation of PFC (Predictive Functional control) in a petrochemical plant 19

Implementation of PFC (Predictive Functional Control) in a p...

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19th IFAC World Congress on International Federation of Automatic control, IFAC 2014

作者： Haber, R. Schmitz, U. Zabet, K. Institute of Process Engineering and Plant Design Laboratory of Process Automation Cologne University of Applied Science Betzdorfer Str. 2 KölnD-50679 Germany Department for APC and Process Control Technology Rheinland Refinery Shell Deutschland Oil GmbH Ludwigshafener Strasse 1 WesselingD-50389 Germany

ISBN: (纸本)9783902823625

PFC (Predictive Functional control) is a simple but very effective SISO (Single-Input SingleOutput) predictive controller which does not require any matrix inversion or numerical minimization of a cost function, therefore it is easy to realize in a PLCs (Programmable Logical controllers) or a DCS (Decentralized control Systems). The manipulated variable and/or its increment, as well other variables can be constrained easier than when using PI(D) (Proportional, Integrating, and Derivating) controller. Furthermore PFC handles the dead time process better than with PI(D) controller. Three industrial applications of PFC for two distillation columns and a reactor in a petro-chemical plant were implemented and the experiences are presented here. © IFAC.

关键词： controllers

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Corrigendum to “Limit load solutions of thick-walled cylinders with fully circumferential cracks under combined internal pressure and axial tension” [Nucl. Eng. Des. 238 (2008) 2155–2164]

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Nuclear engineering and Design 2015年 284卷 309-309页

作者： Zengliang Gao Gangsi Cai Lihua Liang Yuebao Lei Institute of Process Equipment and Control Engineering Zhejiang University of Technology The MOE Key Laboratory of Mechanical Manufacture and Automation Hangzhou 310032 China Wenzhou Industry Design Institute Wenzhou 325000 China

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