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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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Attitude synchronization for multiple flexible spacecraft based on non-smooth control 19

Attitude synchronization for multiple flexible spacecraft ba...

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

作者： Du, Haibo He, Yigang Li, Shihua Cheng, Yingying Chen, Xisong School of Electrical Engineering and Automation Hefei University of Technology Hefei230009 China Key Laboratory of Measurement and Control of Complex Systems of Engineering Ministry of Education Southeast University Nanjing210096 China

ISBN: (纸本)9783902823625

This paper considers the problem of attitude synchronization for a group of flexible spacecraft based on distributed attitude cooperative control strategy. Based on the backstepping design, non-smooth control, and the neighbor-based design rule, a distributed attitude control law is constructed step by step. Under the proposed control law, it is shown that the attitude synchronization is achieved asymptotically and the induced vibration by flexible appendages is simultaneously suppressed. © IFAC.

关键词： control theory

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Adaptive fuzzy control of output-constrained switched nonlinear systems

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ICIC Express Letters 2015年第12期9卷 3355-3362页

作者： Niu, Ben Liu, Yanli Shen, Mouquan School of Control Science and Engineering Dalian University of Technology No. 2 Linggong Road Ganjingzi District Dalian China College of Mathematics and Physics Bohai University No. 19 Keji Road New Songshan District Jinzhou China Automation Research Institute Bohai University No. 19 Keji Road New Songshan District Jinzhou China College of Electrical Engineering and Control Science Nanjing Technology University Nanjing China Key Laboratory of Measurement and Control of Complex Systems of Engineering Ministry of Education Nanjing China

In this paper, the problem of adaptive fuzzy tracking control is considered of uncertain switched nonlinear systems with an output constraint. First, a barrier Lyapunov function (BLF) is employed to deal with the output constraint. Then fuzzy logic systems are used to approximate the unknown nonlinearities and backstepping technique is employed to construct an adaptive fuzzy controller. The designed controller guarantees all the closed-loop signals remain bounded while the system output converges to a small neighborhood of the desired reference signal without violating the constraint. An example is given to demonstrate the validity of the developed result. © 2015 ICIC International.

关键词： Lyapunov functions

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State Estimation of Finite-State Hidden Markov Models Subject to Stochastically Event-triggered measurements

State Estimation of Finite-State Hidden Markov Models Subjec...

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IEEE Annual Conference on Decision and control

作者： Wentao Chen Junzheng Wang Ling Shi Dawei Shi State Key Laboratory of Intelligent Control and Decision of Complex Systems School of Automation Beijing Institute of Technology Beijing 100081 P.R. China Department of Electronic and Computer Engineering Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong

ISBN: (纸本)9781479978878

We consider the event-triggered state estimation of a finite-state hidden Markov model with a general stochastic event-triggering condition. Utilizing the change of probability measure approach and the event-triggered measurement information available to the estimator, analytical expressions for the conditional probability distributions of the states are obtained, based on which the minimum mean square error event-based state estimates are further calculated. We show that the results also cover the case of packet dropout, under a special parameterization of the event-triggering conditions. With the results on state estimation, a closed-form expression of the average sensor-to-estimator communication rate is also presented. The effectiveness of the proposed results is illustrated by a numerical example and comparative simulations.

关键词： State estimation Hidden Markov models Event trigger Probability distribution Mean square error numerical example

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Asymptotical stabilization of linear distributed parameter switched systems

Asymptotical stabilization of linear distributed parameter s...

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第26届中国控制与决策会议

作者： Leping Bao Shumin Fei Key Laboratory of Measurement and Control of Complex Systems of Engineering Ministry of Education School of Automation Southeast University

In this paper, the asymptotical stabilization problem for ordinary differential equations switched systems has been extended to distributed parameter switched systems(DPSS) in Hilbert space. Based on semigroup and operator theory, sufficient conditions of asymptotical stabilization for linear DPSS are derived in linear operator inequalities(LOIs)framework. Being applied to three dimensional switched heat propagation equations, we transform the LOIs into the linear matrix inequalities(LMIs), which has the advantage of being numerically well tractable by using matlab software. In particular, the state feedback gain matrices are designed. Two examples are given to illustrate the proposed results.

关键词： Distributed parameter switched system,semigroup,Lyapunov function,asymptotical stabilization,linear operator inequalities.

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Sensitivity Analysis of Optimal control Problems for Switched systems

Sensitivity Analysis of Optimal Control Problems for Switche...

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第26届中国控制与决策会议

作者： Jinjin Liu Kanjian Zhang Xiaomei Liu Haikun Wei School of Automation Southeast University Key Laboratory of Measurement and Control of Complex Systems of Engineering Ministry of EducationSoutheast University

ISBN: (纸本)9781479937097

This paper investigates the problem of sensitivity analysis for switched autonomous systems involving uncertain parameters. The aim is to find switching instants which minimizes the cost function, and meanwhile makes it robust to the variation of the original objective with respect to unknown parameters. We focus on the fixed switching mode sequences and convert the sensitivity problem into a conventional optimal switched control problem, which can be solved directly using the gradient descent algorithm. The efficacy of the proposed method is illustrated via numerical example.

关键词： Switched systems,Sensitivity analysis,Optimal control,Parameter variation

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Paint Deposition Modeling with Variable Parameters for Spray Painting Robots

Paint Deposition Modeling with Variable Parameters for Spray...

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2014 International Conference on Electrical,control and automation(ICECA 2014)

作者： Liuhao Ge Zhengda Meng School of Automation Southeast University Key Laboratory of Measurement and Control of Complex Systems of Engineering Ministry of EducationSoutheast University

Current paint deposition modeling approaches did not consider the influence of variable spraying parameters. As spray painting robot has been widely used in paint application, there is a great need to be able to generate paint deposition model efficiently for robot path planning and simulation. In this paper, a layered framework for paint deposition modeling system is proposed, which uses the Back-Propagation（BP） neural network to model the relationship between spraying parameters（flow rate and atomizing pressure） and the paint deposition model. By using this modeling system, it isn’t necessary for users to conduct extra experiments when flow rate and atomizing pressure change. According to results of experiment and simulation, this method can predict paint deposition rate effectively.

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Adaptive fault-tolerant controller design for airbreathing hypersonic vehicle with input saturation

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Journal of systems engineering and Electronics 2013年第3期24卷 488-499页

作者： Haibin Sun Shihua Li Changyin Sun Key Laboratory of Measurement and Control of Complex Systems of Engineering(Ministry of Education) School of AutomationSoutheast University

The problem of fault-tolerant control is discussed for the longitudinal model of an airbreathing hypersonic vehicle （AHV） with actuator faults and external disturbances. Firstly, a fault-tolerant control strategy is presented for the longitudinal model of an AHV, which guarantees that velocity and altitude track their reference trajectories at an exponential convergence rate. However, this method needs to know the minimum value of the actuator efficiency factor and the upper bound of the external disturbances, which makes it not easy to implement. Then an improved adaptive fault-tolerant control scheme is proposed, where two adaptive laws are employed to estimate the upper bound of the external disturbances and the minimum value of the actuator efficiency factor, respectively. Secondly, the problem of designing a control scheme with control constraints is further considered, and a new adaptive fault-tolerant control strategy with input saturation is designed to guarantee that velocity and altitude track their reference trajectories. Finally, simulation results are given to show the effectiveness of the proposed methods.

关键词： airbreathing hypersonic vehicle （AHV） fault-tolerant control （FTC） adaptive control input saturation.

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Improved Stability Criteria on Discrete-time systems with Time-varying and Distributed Delays

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International Journal of automation and computing 2013年第3期10卷 260-266页

作者： Ting Wang Ming-Xiang Xue Chun Zhang Shu-Min Fei Key Laboratory of Measurement and Control of Complex Systems of Engineering School of Automation Southeast University

This work was supported by National Natural Science Foun- dation of China （Nos. 60905009, 61004032, 61104119, 61174076, and 61172135）, and Jiangsu Province Natural Science Foundation （Nos. SBK201240801 and BK20123... 详细信息

关键词： Discrete-time system global stability interval time-varying delay distributed delay reciprocal convex technique.

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Robust control reconfiguration of resource allocation systems with Petri nets and integer programming

Robust control reconfiguration of resource allocation system...

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作者： Li, Jun Zhou, Mengchu Guo, Tao Gan, Yahui Dai, Xianzhong Key Laboratory of Measurement and Control of Complex Systems of Engineering Ministry of Education China School of Automation Southeast University Nanjing 210096 China Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai 201804 China Department of Electrical and Computer Engineering New Jersey Institute of Technology Newark NJ 07102 United States

Supervisory control reconfiguration can handle the uncertainties including resource failures and task changes in discrete event systems. It was not addressed to exploit the robustness of closed-loop systems to accommodate some uncertainties in the prior studies. Such exploitation can cost-efficiently achieve reconfigurability and flexibility for real systems. This paper presents a robust reconfiguration method based on Petri nets (PNs) and integer programming for supervisory control of resource allocation systems (RASs) subject to varying resource allocation relationships. An allocation relationship is seen as a control specification while the execution processes requiring resources as an uncontrolled plant. First, a robust reconfiguration mechanism is proposed. It includes updating the P-invariant-based supervisor and evolving the state of the closed-loop system. The latter adapts to the control specification changes by the self-regulation of the closed-loop system's state. Next, two novel integer programming models for control reconfiguration are proposed, called a reconfiguration model with acceptability and reconfiguration one with specification correction. Since both models integrate the firability condition of transitions, no additional efforts are required for the state reachability analysis. Finally, a hospital emergency service system is used as an example to illustrate them. © 2014 Elsevier Ltd. All rights reserved.

关键词： Integer programming

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