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HS joint statistics based adaptive color segmentation

Dongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Southeast University (Natural Science Edition) 2010年第SUPPL. 1期40卷 266-271页

作者： Li, Jun Meng, Zhengda School of Automation Southeast University Nanjing 210096 China Key Laboratory of Measurement and Control of Complex Systems of Engineering of Ministry of Edu. Southeast University Nanjing 210096 China

An adaptive threshold segmentation algorithm based on HS joint statistics using HSI color model is introduced in order to improve the performance of image segmentation and the robustness of object recognition to illumination change. Statistics of H and S component value of all the pixels in the region of interest (ROI) is obtained after image segmentation in HSI color space. The changing rule of statistics is verified while an empirical scale factor is applied to reflect the difference between the influence of H value and S value on segmentation threshold. The threshold is thus adjusted online according to the proposed approach. Experimental results demonstrate the decrease trend of H and S component value with intensified light. Furthermore, it validates the robustness of the approach under the circumstance of changing illumination. Thus the accuracy of the vision-based robot grasping is significantly improved.

关键词： Image segmentation

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Feedback controller designed for hybrid network control system with adaptation to delay parameter

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Dongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Southeast University (Natural Science Edition) 2010年第SUPPL. 1期40卷 19-24页

作者： Chai, Lin Fei, Shumin Zhai, Junyong Jin, Haiyan Wang, Ruimin Li, Yanhong School of Automation Southeast University Nanjing 210096 China Key Laboratory of Measurement and Control of Complex Systems of Engineering of Ministry of Edu. Southeast University Nanjing 210096 China

A class of complex hybrid time-delay models for network control systems have been constructed by taking the characteristics of network into account. Based on a LMI(linear matrix inequality) method, a kind of Lyapunov-Krasovskii functional is employed, and the controller design is discussed for this type of systems. As input control is in discrete-time and the input delay constant is known, while state is in continuous-time and the state delay constant is not known exactly, so the system is constructed based on two models in both continuous-time domain and discrete-time domain. At the same time, a new type of adaptive control strategy for the unknown delay parameter is proposed in this paper, which realizes that the unknown delay parameter can always be reflected in the memory state-feedback controller. Delay-dependent sufficient conditions for the existence of the feedback controller in terms of LMIS are obtained.

关键词： Linear matrix inequalities

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Conceptual maps based navigation for mobile robots

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Dongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Southeast University (Natural Science Edition) 2010年第SUPPL. 1期40卷 144-148页

作者： Qian, Kun Ma, Xudong Dai, Xianzhong School of Automation Southeast University Nanjing 210096 China Key Laboratory of Measurement and Control for Complex Systems of Engineering of Ministry of Edu. Southeast University Nanjing 210096 China

A conceptual map model of environments is proposed for task planning of service robots in semantic knowledge space. Such model is characterized with a layered structure containing ontology, spatial and user knowledge. It is capable of inferring environmental knowledge and mapping semantic plans onto the instantial perception space. A scene recognition based method for conceptual map building and updating is proposed to support the environment learning capabilities of robots. Using such model, a layered topological and metric navigation strategy is proposed, in which map switching technique ensures that Monte Carlo localization and metric path planning are performed within each small-scale grid map. Experimental results in large-scale office environments validate the effectiveness and efficiency of robot localization and navigation, and a semantic navigation manner is achieved.

关键词： Navigation

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Scale adaptable mean shift object tracking based on image fragments

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Dongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Southeast University (Natural Science Edition) 2010年第SUPPL. 1期40卷 131-135页

作者： Wang, Aqin Yang, Wankou Sun, Changyin School of Automation Southeast University Nanjing 210096 China Key Laboratory of Measurement and Control for Complex Systems of Engineering of Ministry of Edu. Southeast University Nanjing 210096 China

The classical mean shift tracking algorithm is apt to make errors or lose the target if the target is occluded for a very long time. Thus an improved mean shift tracking algorithm is proposed. This algorithm divides the target into multiple fragments and integrates spatial information by using different weights of each image fragment. The similarity coefficient between target template and candidate template consists of the Bhattacharyya coefficients of the corresponding multiple fragments. Experimental results show that the proposed method is efficient when the target is occluded for a long time. A new method named edge-histogram is used. This method is based on original scale updating mechanism and make a further judgment that whether the target is smaller or not by calculating the Bhattacharyya coefficient between the target's edge-histograms of the current frame and the previous one. Experimental results show that the proposed algorithm can deal with the scale problem very well.

关键词： Graphic methods

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Intelligent vehicle monitoring system based on WebGIS and mobile video

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Dongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Southeast University (Natural Science Edition) 2010年第SUPPL. 1期40卷 192-197页

作者： Zhou, Hui Ye, Hua Yang, Yanlan School of Automation Southeast University Nanjing 210096 China Key Laboratory of Measurement and Control of Complex Systems of Engineering of Ministry of Edu. Southeast University Nanjing 210096 China

In order to solve the problems of inaccurate positioning in current vehicle monitoring systems, an intelligent vehicle monitoring system based on mobile video and WebGIS (Web geographic information system) is proposed and designed. The system is composed of front-end equipment, system platform and client. The instant image information captured by vehicle mobile video and the GPS(global positioning system) positioning location information received by the terminal are transmitted from front-end to system platform via the GPRS(general packet radio service) mobile communications platform. Also, a highly compressed digital video and audio codec technology standard named H.264/AVC is employed to compress the real-time mobile video information and the Google Maps API is called to display the current position of vehicles on the electronic map. Furthermore, the spatial analysis capabilities of GIS plus the GPS information not only make tracking feasibly, but also provide aid in decision making. It is shown that the system can not only reproduce the video data timely and accurately, but also accurately position the mobile vehicles so as to provide a better service in monitoring, control, management, analysis, decision-making and command functions, which expands the application fields and development prospects of WebGIS and mobile video monitoring technology.

关键词： Global positioning system

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Smooth path design for mobile service robots based on improved A* algorithm

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Dongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Southeast University (Natural Science Edition) 2010年第SUPPL. 1期40卷 155-161页

作者： Shan, Wei Meng, Zhengda School of Automation Southeast University Nanjing 210096 China Key Laboratory of Measurement and Control of Complex Systems of Engineering of Ministry of Edu. Southeast University Nanjing 210096 China

When it comes to the issue of path planning for mobile service robots in structured indoor environments, traditional A* algorithm fails to display a good performance of real-time path tracking. Therefore, a new method is proposed to design a near-optimal smooth path. Mobile robots can thus track the path smoothly and reach the goal fast. At first, the improved A* algorithm is applied to plan a proper trajectory for the mobile robot. Then a key-point optimization process is applied to make the global path simplified to be connections among a series of key points. The most important improvement lies in the introduction of the polar polynomials curve to smooth the path according to the constraints of position, curvature and slope. However, when the arc turns become 90° or more, the optimized piecewise-polynomial-function curve is generated to replace the original one. Experimental results prove that the path generated meets the dynamic characteristics of the mobile robots as well as the geometric features. The requirements of quick real-time computation of path tracking process can be well satisfied.

关键词： Mobile robots

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Applications of Berkeley DB in home energy monitor system

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Dongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Southeast University (Natural Science Edition) 2010年第SUPPL. 1期40卷 92-97页

作者： Bao, Jing Ye, Hua Sun, Xiaojie Li, Jian School of Automation Southeast University Nanjing 210096 China Key Laboratory of Measurement and Control of Complex Systems of Engineering of Ministry of Edu. Southeast University Nanjing 210096 China

In order to achieve the goal of data statistic and task management under the embedded systems, together with the consideration of processing speed and the internal storage capacity, the embedded database is introduced. The features of embedded database are small in size, multi-functional, portable, highly efficient and stable. Taking the data management in the home energy monitor system as an example, a statistical method of time sharing is proposed. The embedded database Berkeley DB is transplanted, and the resource occupancy and response speed before and after using Berkeley DB are compared. Testing data show that although taking up more storage resources, the use of Berkeley DB provides more efficient data management capabilities. The application of Berkeley DB improves the system response, and provides a better human-computer interaction. Under the allowance of the hardware resources of device, this practice of using space for performance is feasible.

关键词： Information management

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Internal model control for hysteretic nonlinear systems based on support vector regression

Internal model control for hysteretic nonlinear systems base...

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World Congress on Intelligent control and automation (WCICA)

作者： Wenguang Zhang Jianqin Mao Yanhua Ma Beijing Key Laboratory of Measurement and Control Technology and System for Industrial Process Control & Computer Engineering School North China Electric Power University Beijing China School of Automation Science and Electrical Engineering Beijing Aeronautics and Astronautics University Beijing China

Aim at the hysteretic nonlinearity characteristic of the giant magnetostrictive actuator in control, an internal model control method based on support vector regression is presented in this paper. Its models are built by support vector regression using the input and output data of the actuator and the internal model control is achieved. The simulation results show the method in this paper has better control precision.

关键词： Support vector machines Actuators automation Data models Computational modeling Hysteresis Magnetostriction

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Adaptive Tracking control of Underactuated Quadrotor Unmanned Aerial Vehicles via Backstepping

Adaptive Tracking Control of Underactuated Quadrotor Unmanne...

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American control Conference

作者： Mu Huang Bin Xian Chen Diao Kaiyan Yang Yu Feng Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University Tianjin 300072 China Chinese State Nuclear Power Technology Corporation LTD Beijing 100140 China

ISBN: (纸本)9781424474264

This paper considers about the control problem for an underactuated quadrotor UAV system with model parameter uncertainty. Backstepping based techniques are utilized to design a nonlinear adaptive controller which can compensate for the mass uncertainty of the vehicle. Lyapunov based stability analysis shows that the proposed control design yields asymptotic tracking for the UAV's motion in x, y, z direction and the yaw rotation, while keep the stability of the closed loop dynamics of the quadrotor UAV. Numerical simulation results are provided to show the good tracking performance of proposed control laws.

关键词： Backstepping design control tracking control Adaptive tracking asymptotic tracking control law visual tracking Stability analysis

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An Optimal control Scheme for a Class of Discrete-time Nonlinear systems with Time Delays Using Adaptive Dynamic Programming

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Acta Automatica Sinica 2010年第1期36卷 121-129页

作者： Qing-Lai WEI Hua-Guang ZHANG De-Rong LIU Yan ZHAO Key Laboratory of Complex Systems and Intelligence Science Institute of Automation Chinese Academy of Sciences Beijing 100190 P. R. China School of Information Science and Engineering Northeastern University Shenyang 110004 P. R. China Department of Automatic Control Engineering Shenyang Institute of Engineering Shenyang 110136 P. R. China

Abstract In this paper, an optimal control scheme for a class of nonlinear systems with time delays in both state and control variables with respect to a quadratic performance index function is proposed using a new iterative adaptive dynamic programming (ADP) algorithm. By introducing a delay matrix function, the explicit expression of the optimal control is obtained using the dynamic programming theory and the optimal control can iteratively be obtained using the adaptive critic technique. Convergence analysis is presented to prove that the performance index function can reach the optimum by the proposed method. Neural networks are used to approximate the performance index function, compute the optimal control policy, solve delay matrix function, and model the nonlinear system, respectively, for facilitating the implementation of the iterative ADP algorithm. Two examples are given to demonstrate the validity of the proposed optimal control scheme.

关键词： Adaptive dynamic programming (ADP) approximate dynamic programming time delay optimal control nonlinear system neural networks

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