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International Conference on Intelligent Transportation

作者： X. Zhang F. Wang Z. Wang Wei Li D. He Key Laboratory of Complex Systems and Intelligence Science Intelligcnt and Telemalic Systems Division Institute of Automation Chinese Academy and Sciences Beijing China

The structure and principle of an intelligent tire based on wireless passive surface acoustic wave (SAW) sensors are described. The SAW sensor is made by two identical delay lines on both sides of the substrate symmetrically. In each delay line, there were two reflectors with difference distance from interdigital transducer (IDT). The sensor was hermetically sealed in an all-quartz-package (APQ) technology and embedded in the tire. It can measure the tire pressure and temperature parameters automatically. According to the measurement result, the sensor systems can estimate the tire state intelligently and present the driver an alarm when the pressure or temperature was abnormal. The theory of measuring pressure and temperature is discussed and analysis for measures with pressures from 150 kPa to 300 kPa and temperatures from 25/spl deg/C to 95/spl deg/C is conducted. The results of measurement agree with the theory well.

关键词： Intelligent sensors Tires Wireless sensor networks Surface acoustic waves Acoustic waves Acoustic sensors Pressure measurement Temperature sensors Delay lines Intelligent structures

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Swing-free transporting of two-dimensional overhead crane using sliding mode fuzzy control

Swing-free transporting of two-dimensional overhead crane us...

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American Control Conference (ACC)

作者： Diantong Liu Jianqiang Yi Dongbin Zhao Wei Wang Key Laboratory of Complex Systems and Intelligence Science Institution of Automation Chinese Academy and Sciences Beijing China College of computer Science Yantai University Yantai China

An adaptive sliding mode fuzzy control approach is proposed for a two-dimensional overhead crane. System linearization transforms the two-dimensional system to two independent systems: X-direction transport system and Y-direction transport system. Both the two systems are with the same dynamic model and both include two subsystems: positioning subsystem and anti-swing subsystem. A sliding mode fuzzy control approach is proposed for both X-direction transport and Y-direction transport, and it combines SMC's robustness and FLC's independence of system model. According to the influences on system dynamic performance, both of the slope of sliding mode surface and the relationship between subsystems are automatically tuned by real time fuzzy inference respectively. The effectiveness of the proposed control is demonstrated by experiments with a two-dimensional prototype overhead crane.

关键词： Cranes Fuzzy control Sliding mode control Programmable control Adaptive control Robust control Real time systems Fuzzy systems Automatic control Prototypes

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Driver assisted fuzzy control of yaw dynamics for 4WD vehicles

Driver assisted fuzzy control of yaw dynamics for 4WD vehicl...

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IEEE Symposium on Intelligent Vehicle

作者： Qunzhi Zhou Feiyue Wang Key Laboratory of Complex Systems and Intelligent Science Institute of Automation Chinese Academy and Sciences Beijing China Department of systems and Industrial Engineering University of Arizona Tucson USA

ISBN: (纸本)0780383109

A new model for four wheel driving (4WD) vehicles and a fuzzy control system that enhances vehicle yaw stability especially in fast evasive maneuvers performed to the safety limit are developed. The driver handles the front steering angle over a turn, while the controller commands the braking forces of individual wheels and rear steering effort. This mitigates the vehicle's oversteer or understeer tendencies during emergent cornering situation. The fuzzy controller is firstly established by qualitative analysis of the dynamics of the vehicle and tires. The available control authority and effect are then evaluated by implementing the controller on the 4WD vehicle model developed before using computer simulation. The simulation results demonstrate the benefit of the proposed control method in terms of improved vehicle response. Specifically, the method is practical for it is simpleness and robustness.

关键词： Fuzzy control Vehicle dynamics Vehicle driving Vehicle safety Vehicles Wheels Stability Force control Tires Computer simulation

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Improving fingerprint recognition performance based on feature fusion and adaptive registration pattern

Lecture Notes in Computer Science (including subseries Lectu...

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Lecture Notes in Computer science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 2004年 3338卷 57-66页

作者： Tian, Jie He, Yuliang Yang, Xin Li, Ang Chen, XinJian Biometrics Research Group Key Laboratory of Complex Systems and Intelligence Science Institute of Automation P.O.Box 2728 Beijing 100080 China Graduate School Chinese Academy of Science Beijing 100039 China

This paper proposes an adaptive registration pattern based fingerprint matching method dealing with the non-linear deformations in fingerprint. The "registration pattern" between two fingerprints is the optimal registration of every part of one fingerprint with respect to the other fingerprint. Registration patterns generated from imposter's matching attempts are different from those patterns from genuine matching attempts, although they share some similarities in the aspect of minutiae. In this paper, we combine minutiae, associate ridges and orientation fields to determine the registration pattern between two fingerprints and match them. The proposed matching scheme has two stages. An offline, training stage, derives a genuine registration pattern base from a set of genuine matching attempts. Then, an online matching stage registers the two fingerprints and determines the registration pattern. A further fine matching is conducted. In addition, the block orientation field is used as the global feature of a fingerprint to improve the performance of this method. And 2nd and 3rd relational structures between minutiae are applied to promote the fingerprint matching method. Experimental results evaluated by FVC2004 demonstrate that the proposed algorithm is an accurate one. © Springer-Verlag Berlin Heidelberg 2004.

关键词： Pattern matching

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Transformation-variants estimation using similarity relative histogram grouping model

Lecture Notes in Computer Science (including subseries Lectu...

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Lecture Notes in Computer science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 2004年 3338卷 471-480页

作者： He, Yuliang Tian, Jie Biometrics Research Group Key Laboratory of Complex Systems and Intelligence Science Institute of Automation P.O.Box 2728 Beijing 100080 China Graduate School Chinese Academy of Science Beijing 100039 China

This paper proposes a novel method that estimates parameters of a geometric transformation by means of grouping and statistical inference in relative histogram grouping models borrowed from the law of large number. Since an image is divided into many local partial objects, each of which is represented by groups of transformation-invariant and transformation-variant (e.g., translation, rotation, and shearing) and whose deformations are considered to be linear, we construct minutiae-simplexes to represent partial objects in a fingerprint. A relative histogram grouping model describes the relationship between transformation-invariant and variant. Even if the image is transformed at random, partial objects still maintain their linear representation, from which the relative histogram techniques extract grouping centers that account for transformation-variations in partial objects for geometric alignment. Our promising experimental results show that our technique is efficient in alignment and match. © Springer-Verlag Berlin Heidelberg 2004.

关键词： Linear transformations

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A new kind of real-time control scheduling algorithm

A new kind of real-time control scheduling algorithm

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International Conference on Control, Automation, Robotics and Vision (ICARCV)

作者： Jian Song Dong-Zhi He Wei Li College of Network Education Lanzhou University of Technology Lanzhou China The Key Laboratory of Complex Systems and Intelligence Science Institute of Automation Chinese Academy and Sciences Beijing China

ISBN: (纸本)0780386531

Many application specific operating systems based on system on chip are composed of lots of tasks that can generate multi-tasking using preemptive scheduling. Preemptive multi-tasking incurs high preemption switching overheads, and these costs may jeopardize the system schedulability. In this paper, a novel scheduling, named dynamic preemption threshold, is proposed. The scheduling can reduce preemption costs by thread assignment and changing task dynamic preemption threshold at runtime. Because dynamic preemption threshold is based on dynamic algorithm, it can achieve higher processor utilization with relative low costs in context switching and memory requirement. The scheduling perfectly integrates preemption threshold scheduling into EDF algorithm, and accomplishes to transform static model to dynamic algorithm seamlessly.

关键词： Scheduling algorithm Processor scheduling Dynamic scheduling Object oriented modeling Random access memory Costs Runtime Read-write memory Heuristic algorithms Real time systems

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Hybrid earliest deadline first/preemption threshold scheduling for real-time systems

Hybrid earliest deadline first/preemption threshold scheduli...

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International Conference on Machine Learning and Cybernetics (ICMLC)

作者： Dong-Zhi He Fei-Yue Wang Wei Li Xiang-Wen Zhang The Key Laboratory of Complex Systems and Intelligence Science Institute of Automation Chinese Academy and Sciences Beijing China The Department of Systems and Industrial engineering University of Arizona Tucson Tucson AZ USA Institute of Automation Chinese Academy of Sciences Beijing Beijing CN

ISBN: (纸本)0780384032

As embedded systems are getting increasingly complex, preemption overheads become a serious load problem for many microchip-based application specific systems, and sometimes may even jeopardize the system schedulability. This paper presents a dynamic preemption threshold scheduling (DPT) that integrates the preemption threshold scheduling into the earliest deadline first The DPT scheduling can effectively reduce context switching by threads assignment and changing the task dynamic preemption threshold at runtime. Meanwhile, because the algorithm is based on dynamic scheduling, it can achieve higher processor utilization with relatively low costs in preemption switching and memory requirements. The DPT scheduling can also perfectly schedule a mixed task set with preemptive and non-preemptive tasks, and subsumes both as special cases.

关键词： Real time systems Job shop scheduling Dynamic scheduling Processor scheduling Runtime Scheduling algorithm Control systems Embedded system Operating systems Costs

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Hierarchical structure description of spatiotemporal chaos

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Physical Review E 2004年第3期70卷 036215-036215页

作者： Jian Liu Zhen-Su She Hongyu Guo Liang Li Qi Ouyang State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engineering Science Peking University Beijing 100871 People's Republic of China Department of Mathematics UCLA Los Angeles California 90095 USA Department of Physics Peking University Beijing 100871 People's Republic of China

We develop a hierarchical structure (HS) analysis for quantitative description of statistical states of spatially extended systems. Examples discussed here include an experimental reaction-diffusion system with Belousov-Zhabotinsky kinetics, the two-dimensional complex Ginzburg-Landau equation, and the modified FitzHugh-Nagumon equation, which all show complex dynamics of spirals and defects. We demonstrate that the spatial-temporal fluctuation fields in the above-mentioned systems all display the HS similarity property originally proposed for the study of fully developed turbulence [Z.-S. She and E. Leveque, Phys. Rev. Lett. 72, 336 (1994)]. The derived values of a HS parameter β from experimental and numerical data in various physical regimes exhibit consistent trends and characterize the degree of turbulence in the systems near the transition, and the degree of heterogeneity of multiple disorders far from the transition. It is suggested that the HS analysis offers a useful quantitative description for the complex dynamics of two-dimensional spatiotemporal patterns.

关键词： Chaos theory

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Reynolds stress model involving the mean spin tensor

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Physical Review E 2004年第3期70卷 036302-036302页

作者： Yu-Ning Huang Hui-Yang Ma State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering Science Peking University Beijing 100871 People’s Republic of China Department of Physics Graduate School of the Chinese Academy of Sciences P. O. Box 3908 Beijing 100039 People’s Republic of China

In this work, we develop a Reynolds stress model along the line of the approach presented by Huang [Commun. Nonlinear Sci. Numer. Simul. 9, 543 (2004)], aiming to assess the role and contribution of the mean spin tensor in turbulence modeling. Here, the constitutive functional for the Reynolds stress depends on the mean spin tensor as well as the mean stretching tensor and its Jaumann derivative, the turbulent kinetic energy K, and the turbulent dissipation rate ε, which is at the complexity level of p=1,m=1, and n=0 of a rate-type constitutive equation for the Reynolds stress proposed in the aforementioned paper. The explicit form for the Reynolds stress is obtained with recourse to the representation theorem and the theory of invariants developed in modern rational continuum mechanics, and, as an approximation, a nonlinear cubic K−ε model is worked out in which the model coefficients are analytically identified based on the experimental results of Tavoularis and Corrsin [J. Fluid Mech. 104, 311 (1981)]. In addition, numerical results based on this model, in the forms of employing the Jaumann derivative and the Oldroyd derivative, respectively, for homogeneous turbulent shear flow and fully developed turbulent flow over a backward-facing step, are presented in comparison with those obtained based on a few previously proposed linear and nonlinear K−ε models, showing reasonably good agreement with the experimental results and the DNS data concerned and a better performance than the previously developed quadratic models.

关键词： TURBULENT SECONDARY FLOWS CHANNEL FLOW SIMULATION NUMBER ENERGY channel flow STRESS MODEL Spin Energy sources simulating Tensor Turbulent shear flow Turbulent Flow Reynolds stress

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Extraction of Plumes in Turbulent Thermal Convection

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Physical Review Letters 2004年第12期93卷 124501-124501页

作者： Emily S. C. Ching H. Guo Xiao-Dong Shang P. Tong and Ke-Qing Xia Department of Physics The Chinese University of Hong Kong Shatin Hong Kong People's Republic of China State Key Laboratory for Studies of Turbulence and Complex Systems Dept. of Mech. and Engin. Sci. Peking University Beijing 100871 People’s Republic of China Department of Physics Oklahoma State University Stillwater Oklahoma 74078 USA Department of Physics Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong People's Republic of China

We present a scheme to extract the velocity of buoyant structures in turbulent thermal convection from simultaneous local velocity and temperature measurements. Applying this scheme to measurements taken at positions within the convection cell where the buoyant structures are dominated by plumes, we obtain the temperature dependence of the plume velocity and understand our results using the equations of motion. We further obtain the scaling behavior of the average local heat flux in the vertical direction at the cell center with the Rayleigh number and find that the scaling exponent is different from that measured for the Nusselt number. This difference leads to the conclusion that heat cannot be mainly transported through the central region of the convection cell.

关键词： .central region temperature measurements Buoyant local velocity vertical direction cell center convection cell turbulent thermal plume velocity local heat flux mainly transported

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