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Analysis of security in cyber-physical systems

Science China. Technological Sciences 2017年第12期60卷 1975-1977页

作者： Chen Jie Zhang Fan Sun Jian School of Automation Beijing Institute of Technology State Key Laboratory of Intelligent Control and Decision of Complex Systems Beijing 100081

In recent years, cyber-physical systems (CPSs) have received much attention from both the academic world and the industrial world, which refer to a deep integration and coordination of physical and computational resources [1,2]. Typical examples of CPSs can be found in smart grids, smart transportation systems, industrial control systems, water supply systems, and so on. Furthermore, many military systems are also CPSs. The key characteristic of CPSs is the integration of computing, control and communication. The increased interconnection between the cyber and physical spaces make CPSs vulnerable to various malicious attacks. A well-known example of an attack of CPSs is the Stuxnet which infected the control system of nuclear-fuel centrifuges of Bushehr nuclear power plant in Iran. Stuxnet makes people beware of the grave consequences of a cyber-attack on a CPS. Since many national critical infrastructures are applications of CPS, ensuring security and safety of such systems is of great importance.

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Torque Ripple Reduction of a Modular-Stator Outer-Rotor Flux-Switching Permanent-Magnet Motor

Torque Ripple Reduction of a Modular-Stator Outer-Rotor Flux...

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Annual Conference of the IEEE Industrial Electronics Society

作者： Jing Zhao Yun Zheng Congcong Zhu Hao Chen Liu Yang Key laboratory for Intelligent Control & Decision of Complex Systems Beijing Institute of Technology Beijing China

In order to reduce the permanent magnet (PM) volume and combine the advantages of in-wheel motor, a novel modular-stator outer-rotor flux-switching permanent-magnet motor (MSOR-FSPM) whose PM volume is half of that in conventional outer-rotor flux-switching permanent-magnet (COR-FSPM) motor is proposed. However, cogging torque and torque ripple of MSOR-FSPM motor are especially worse due to the inherent double salient effect and the back-EMF harmonics caused by module stator structure. In this paper, structure and operation principle of MSOR-FSPM motor are described simply. Secondly, cogging torque and torque ripple are reduced by using traditional rotor two-step skewing method, but the result is unsatisfactory. Thirdly, a new rotor two-step skewing method is adopted since the ratio of back-EMF period to cogging torque period is the odd. Compared with traditional rotor step skewing method, the new method eliminates the even harmonics of back-EMF and remains the amplitude of fundamental waveform;the odd harmonics of cogging torque and electromagnetic torque are eliminated. Finally, the results of the new rotor step skewing method is verified by 3D finite element method (FEM) and further improved by embedding non-magnetic blocks in the middle of the stator and rotor.

关键词： Rotors Torque Forging Harmonic analysis Brushless motors Torque measurement AC motors

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Design and analysis of a novel double-sided five-phase modular linear permanent magnet machine

Design and analysis of a novel double-sided five-phase modul...

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Annual Conference of Industrial Electronics Society

作者： keyu Guo Jing Zhao Xiangdong Liu Liu Yang Hao Chen Key laboratory for Intelligent Control & Decision of Complex Systems Beijing Institute of Technology Beijing China

In this paper, in order to replace a conventional electric linear actuator which is consist of rotary PM machine and ball screw, a novel double-sided five-phase modular linear permanent magnet synchronous machine (MLPMSM) is proposed and designed with the same volume. The basic structure of the machine is firstly described and the major dimensions of one module are then optimized to acquire the largest thrust force. Through these methods, the average force of the MLPMSM reaches 206N, which is 58.4% larger than the conventional linear actuator. After that, the 5 th order harmonic in thrust ripple is analyzed and diminished by adjusting the distance between slot openings of the module. As the result the 5 th order harmonic is diminished greatly by 57%.

关键词： Force Optimization Stator cores Actuators Harmonic analysis Iron

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Smooth controller design for non-linear systems using multiple fixed models

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IET control Theory & Applications 2017年第9期11卷 1467-1473页

作者： Jie Chen Wei Chen Jian Sun The Key Laboratory of Intelligent Control and Decision of Complex System School of Automation Beijing Institute of Technology Beijing People's Republic of China Science and Technology on Electronic Information Control Laboratory Chengdu People's Republic of China

Multiple model adaptive control (MMAC) with second-level adaptation is a recently proposed methodology for dealing with systems where the parametric uncertainty is large. Compared with the multiple model switching scheme, the new scheme can lead to significant improvements in performance. Some research has been conducted using the new scheme, but all of the results concern linear systems with an adaptive identification model set. In this study, MMAC with second-level adaptation scheme is extended to non-linear systems in strict feedback form, and the fixed identification model set is under consideration. This is motivated by the fact that a smooth controller can lead to smooth performance and the fixed identification model set gains potential advantages over the adaptive identification model set, especially for the case that the parameters of the system change over the time. Design details are presented and the stability of MMAC with second-level adaptation using a fixed identification model set for non-linear systems is given, which has not been discussed before. Finally, two simulations are performed to show that this scheme performs much better than conventional schemes, including adaptive control and multiple-model switching schemes, in terms of convergence speed and transient performance.

关键词： nonlinear control systems control system synthesis adaptive control uncertain systems linear systems identification convergence transient performance convergence speed fixed identification model set second-level adaptation scheme adaptive identification model set linear systems multiple model switching scheme parametric uncertainty MMAC multiple model adaptive control multiple fixed models nonlinear systems smooth controller design

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Adaptive optimal control for a class of uncertain systems with saturating actuators and external disturbance using integral reinforcement learning

Adaptive optimal control for a class of uncertain systems wi...

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Asian control Conference

作者： Jingang Zhao Minggang Gan Jie Chen Dongyang Hou Meng Zhang Yongqiang Bai State Key Laboratory of Intelligent Control and Decision of Complex Systems Beijing Institute of Technology Beijing

ISBN: (纸本)9781509015740;9781509015733

The problem of adaptive optimal control for a class of nonlinear uncertain systems with saturating actuators and external disturbance is investigated in this paper. Considering the saturating actuators, a non-quadratic cost function is adopted. The key of this optimal control problem is to find the solution to the Hamilton Jacobi Bellman equation (HJB). An online intergral reinforcement learning (IRL) algorithm based-Neural Network (NN) is given to approximate the solution. Unlike traditional integral reinforcement learning algorithms, data onto a period of time stored together with current data are used to update the neural network weights in place of persistence of excitation (PE) condition. This method overcomes the shortcomings of the PE condition which is not easy to be checked online. Finally, numerical examples are given to show the effectiveness of the proposed methods.

关键词： Optimal control Actuators Nonlinear systems Approximation algorithms Artificial neural networks system dynamics

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Adaptive robust controller for electric cylinder with fast parameter estimation based on modified lugre model

Adaptive robust controller for electric cylinder with fast p...

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第36届中国控制会议

作者： Duo yang Li Jun Zheng Wang Ren Jian Hao Shou Kun Wang Wei Shen Key Laboratory of Intelligent Control and Decision of Complex Systems School of Automation Beijing Institute of Technology

In this paper,the adaptive robust control（ARC） algorithm is proposed for tracking control of the electric cylinder *** to the analysis of the working principle of the electric cylinder servo system,the model of the system is established on the modified Lugre friction model,and single observer is designed for calculating friction as *** the ARC controller and adaptive law are designed for on-line parameters estimation,frictional compensation and the suppression external *** the Lyapunov approach,the stability of this system can be obtained in this *** simulation result shows that ARC can suppresses external disturbances effectively and realize real-time online parameter estimation.

关键词： adaptive robust control Lugre model parameter estimation

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Distance-based separability criterion of ROI in classification of farmland hyper-spectral images

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International Journal of Agricultural and Biological Engineering 2017年第5期10卷 177-185页

作者： Tang Jinglei Miao Ronghui Zhang Zhiyong Xin Jing Wang Dong College of Information Engineering Northwest A&F UniversityYangling 712100ShaanxiChina Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi’an University of TechnologyXi’an 710048China College of Information Science and Engineering Shanxi Agricultural UniversityTaigu 030801ShanxiChina

The hyper-spectral image contains spectral and spatial information,which increases the ability and precision of objects *** the classification value of hyper-spectral imaging technology within various applications,users often find it difficult to effectively apply in practice because of the effect of light,temperature and wind in outdoor *** research presented a new classification model for outdoor farmland objects based on near-infrared(NIR)hyper-spectral *** involves two steps including region of interest(ROI)acquisition and establishment of classifiers.A distance-based method for quantitative analysis was proposed to optimize the reference pixels in ROI acquisition *** maximum likelihood(ML)and support vector machine(SVM)were used for farmland objects *** performance of the proposed method showed that the total classification accuracy based on the reference pixels was over 97.5%,of which the SVM-M model could reach 99.5%.The research provided an effective method for outdoor farmland image classification.

关键词： distance-based separability criterion near-infrared hyper-spectral image ROI farmland image classification

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Near-Optimal Online Motion Planning of Connected and Automated Vehicles at a Signal-Free and Lane-Free Intersection

Near-Optimal Online Motion Planning of Connected and Automat...

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2018 IEEE intelligent Vehicles Symposium, IV 2018

作者： Li, Bai Zhang, Youmin Zhang, Yue Jia, Ning Ge, Yuming Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'An University of Technology Xi'an710048 China College of Control Science and Engineering Zhejiang University Hangzhou310027 China Department of Mechanical Industrial and Aerospace Engineering Concordia Institute of Aerospace Design and Innovation Concordia University Montreal Canada Division of Systems Engineering Center for Information and Systems Engineering Boston University BostonMA02215 United States Institute of Systems Engineering Tianjin University Tianjin300072 China China Academy of Information and Communications Technology Beijing100191 China

ISBN: (纸本)9781538644522

In this paper, we propose a cooperative motion planning method for a group of connected and automated vehicles (CAVs) crossing a lane-free intersection without using explicit traffic signaling. This multi-vehicle motion planning task is formulated as a centralized optimal control problem. However, the solution to this optimal control problem is numerically intractable due to the high dimensionality of the collision-avoidance constraints and the nonlinearity of the vehicle kinematics. A two-stage strategy is proposed for generating online solutions: at Stage 1, the CAVs are requested to reach a standard formation before entering the intersection;at Stage 2, the vehicles cross the intersection. As the motion planning sub-problem at Stage 2 begins with a standard configuration, the optimal solution to this standard sub-problem can be computed offline in advance and applied online directly. On the other hand, the formation reconfiguration sub-problem at Stage 1 is easy to solve online. Through dividing the entire dynamic process into two periods, the difficulties in the original optimal control problem are significantly reduced so that the real-time performance is achieved. © 2018 IEEE.

关键词： Motion planning

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Research on weak signal detection based on adaptive multi-stable stochastic resonance under α stable noise

Research on weak signal detection based on adaptive multi-st...

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Annual Conference of Industrial Electronics Society

作者： Shang-bin Jiao Yi Wang Qing Zhang Le Fan Di Sun Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'an China

In this paper, the influences of system parameters on stochastic resonance output effect is analyzed, which takes the multi-stable stochastic resonance system as the model. That is, the vibration condition of multi-stable stochastic resonance system, and weak signal detection method based on the multi-stable stochastic resonance under α stable noise is investigated. Then considering the real-time detection of weak signals in practical engineering, the multi-stable stochastic resonance system parameters a, b, c are optimized by particle swarm optimization(PSO), which takes the output signal-to-noise ratio(SNR out ) as the fitness function. Finally, multi-frequency weak signals detection with α stable noise is achieved, and the above method is applied to the vibration fault diagnosis of turbine. Both simulation and experiment results show that this method can quickly and effectively detect multi-frequency weak signals submerged in strong noise background, which lays a foundation for its application in engineering practice.

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Automatic design of hybrid optimizers based on particle swarm optimization and differential evolution 5

Automatic design of hybrid optimizers based on particle swar...

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5th International Workshop on Advanced Computational Intelligence and intelligent Informatics, IWACIII 2017

作者： Wang, Yipeng Xin, Bin School of Automation Beijing Institute of Technology Beijing100081 China Key Laboratory of Intelligent Control and Decision of Complex Systems Beijing Institute of Technology Beijing100081 China Beijing Advanced Innovation Center for Intelligent Robots and Systems Beijing Institute of Technology Beijing100081 China

Hybridization is termed as an efficient strategy to improve the performance of many optimizers, and the design of efficient hybrids for difficult optimization problems remains a challenging field. In this study, an automatic method is proposed to generate various hybrid optimizers based on particle swarm optimization and differential evolution for a given problem. Based on the unified framework for hybridization proposed in our recent work, the proposed method can provide plenty of hybrid optimizers for a specific problem with given parent optimizers. Besides, an approach which can provide the unified representation of different kinds of hybridization levels is developed. Moreover, all the generated hybrids are evaluated on the CEC2017 benchmark problems, and the results of the statistic analysis and the Wilcoxon's rank-sum tests demonstrate that the hybrid optimizer utilizing the hybridization strategy performs obviously better than the others on the test functions.

关键词： Particle swarm optimization (PSO)

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