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2011 IEEE/RSJ International Conference on Intelligent Robots and Systems

作者： Davide Scaramuzza Andrea Censi Kostas Daniilidis GRASP laboratory Department of Computer and Information Science School of Engineering and Applied Science University of Pennsylvania Philadelphia USA GRASP laboratory University of Pennsylvania USA Control and Dynamical Systems Department Division of Engineering and Applied Sciences California Institute of Technology Pasadena USA

This paper presents a new method to estimate the relative motion of a vehicle from images of a single camera. The biggest problem in visual motion estimation is data association; matched points contain many outliers that must be detected and removed so that the motion can be estimated accurately. A very established method for robust motion estimation in the presence of outliers is the five-point RANSAC algorithm. Five-point RANSAC operates by generating motion hypotheses from randomly-sampled minimal sets of five-point correspondences. These hypotheses are then tested against all data points and the motion hypothesis that after a given number of iterations returns the largest number of inliers is taken as the solution to the problem. A typical drawback of RANSAC is that the number of iterations required to find a suitable solution grows exponentially with the number of outliers, often requiring thousands of iterations for typical data from urban environments. Another problem is that - due to its random nature - sometimes the found solution is not the “best” solution to the motion estimation problem. In this paper, we describe an algorithm for relative motion estimation in the presence of outliers, which does not rely on RANSAC. Contrary to RANSAC, motion hypotheses are not generated from randomly-sampled point correspondences, but from a “proposal distribution” that is built by exploiting the vehicle non-holonomic constraints. We show that not only is the proposed algorithm significantly faster than RANSAC, but that the returned solution may also be better in that it favors the underlying motion model of the vehicle, thus overcoming the typical limitations of RANSAC. Additionally, the proposed algorithm provides the likelihood of the motion estimate, which can be very useful in all those applications where a probability distribution of the position of the vehicle is required (e.g., SLAM). Finally, the performance of the proposed method is compared to that of the sta

关键词： Vehicles Cameras Proposals Motion estimation Wheels Urban areas Three dimensional displays

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The methodology of source disturbances detection on an electroprecipitator example

The methodology of source disturbances detection on an elect...

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International Conference on Electrical Power Quality and Utilisation (EPQU)

作者： Krzysztof Górecki Mirosław Szmajda Janusz Mroczka Department of Electrical Engineering Automatic Control and Computer Science Opole University of Technology Opole Poland Chair of Electronic and Photonic Metrology Wroclaw University of Technology Wroclaw Poland

This paper presents methodology of defining the sources of interferences on the basis of measuring the quality of electrical energy and monitoring the selected parameters of voltage and current waveforms. The presented methodology was based on the example of industrial power network that supplied the new electroprecipitator cooperating with sulphuric acid recovery installation. After a few weeks of proper operation, the Ż electroprecipitator started to report frequent alarms that hindered its effective use. The measurements aimed at specifying the effect of the quality of electrical energy and disturbances occurring in the network on the alarms generated by the electroprecipitator automatic control system. The example shows that as a result of use sophisticated measuring equipment and the analysis of preliminary (short-term) measurements and long-term measurements with the appropriate setting of recording events, it is possible to confirm or reject the hypothesis about the negative effect of low quality energy on the electroprecipitator operation.

关键词： Current measurement Voltage measurement Power quality Energy measurement Transient analysis Time series analysis Histograms

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Evaluation method for heart failure using RR sequence normalized histogram

Evaluation method for heart failure using RR sequence normal...

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computers in Cardiology (CinC)

作者： Chengyu Liu Peng Li Lina Zhao Jing Yang Changchun Liu School of Control Science and Engineering Shandong University Jinan China Shandong Heng-Xin Inspection Technique Exploiture Center Jinan China Department of Computer Science and Technology Shandong University Jinan China

Histogram and scatter plot are important graphical indices for heart rate variability (HRV) analysis. However, they are difficult to quantify the complexity for time series and have little specificity to some cardiovascular diseases. This paper proposed a new graphical method for HRV analysis, which was named as RR sequence normalized histogram. Based on the analysis of RR sequence normalized histogram, three quantitative indices were defined: center-edge ratio (CER), cumulative energy (CE) and range information entropy (RIEn). To verify the validity of the new method, a total of 120 subjects (60 heart failure subjects and 60 healthy control subjects) were enrolled and the three indices were calculated respectively. A Wilcoxon rank sum test showed that: CER (p = 0.232) and CE (p = 0.417) had no statistical differences between heart failure and healthy control group while RIEn (p = 0.027) had. This indicated that the new method had a potential application in evaluating the heart failure and the index RIEn had a better effectiveness than the other two indices.

关键词： Histograms Heart rate variability Indexes Electrocardiography Educational institutions Information entropy

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Size and composition dependence of melting temperature of binary nanoparticles

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science China(Physics,Mechanics & Astronomy) 2011年第5期54卷 897-900页

作者： LU YunBin LIAO ShuZhi XIE Bin CHEN Jia PENG HaoJun ZHANG Chun ZHOU HuiYing XIE HaoWen OUYANG YiFang ZHANG BangWei Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education Department oy rnystcs Hunan Normal University Changsha 410081 China College of Mathematics and Physics University of South China Hengyang 421001 China College of Mathematics and Computer Science Hunan Normal University Changsha 410081 China Computer and Information Engineering School Central South University of Forestry and Technology Changsha 410004 China Department of Physics Guangxi University Nanning 530004 China Department of Applied Physics Hunan University Changsha 410082 China International Centre for Materials Physics Chinese Academy of Sciences Shenyang 110015 China

Based on the ideal solution approximation, the model for size-dependent melting temperature of pure metal nanoparticles is extended to binary alloy systems. The developed model, free of any adjustable parameter, demonstrates that the melting temperature is related to the size and composition of alloy nanoparticles. The melting temperature of CuNi, PbBi and Snln binary alloy nanocrystals is found to be consistent with the experiments and molecular dynamics simulations. The research reveals that alloy nanocrystals have similar melting nature as pure metal.

关键词： nano binary alloy melting temperature size-dependent

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Energy provisioning in wireless rechargeable sensor networks

Energy provisioning in wireless rechargeable sensor networks

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IEEE Annual Joint Conference: INFOCOM, IEEE computer and Communications Societies

作者： Shibo He Jiming Chen Fachang Jiang David K.Y. Yau Guoliang Xing Youxian Sun State Key Laboratory of Industrial Control Technology University of Zhejiang Hangzhou China Department of Computer Sciences Purdue University West Lafayette IN USA Department of Computer Science and Engineering Michigan State University East Lansing MI USA

ISBN: (纸本)9781424499199

Wireless rechargeable sensor networks (WRSNs) have emerged as an alternative to solving the challenges of size and operation time posed by traditional battery-powered systems. In this paper, we study a WRSN built from the industrial wireless identification and sensing platform (WISP) and commercial off-the-shelf RFID readers. The paper-thin WISP tags serve as sensors and can harvest energy from RF signals transmitted by the readers. This kind of WRSNs is highly desirable for indoor sensing and activity recognition, and is gaining attention in the research community. One fundamental question in WRSN design is how to deploy readers in a network to ensure that the WISP tags can harvest sufficient energy for continuous operation. We refer to this issue as the energy provisioning problem. Based on a practical wireless recharge model supported by experimental data, we investigate two forms of the problem: point provisioning and path provisioning. Point provisioning uses the least number of readers to ensure that a static tag placed in any position of the network will receive a sufficient recharge rate for sustained operation. Path provisioning exploits the potential mobility of tags (e.g., those carried by human users) to further reduce the number of readers necessary: mobile tags can harvest excess energy in power-rich regions and store it for later use in power-deficient regions. Our analysis shows that our deployment methods, by exploiting the physical characteristics of wireless recharging, can greatly reduce the number of readers compared with those assuming traditional coverage models.

关键词： Wireless communication Wireless sensor networks RF signals Mathematical model Radiofrequency identification Antennas

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Direct contour error compensation for biaxial contouring control systems based on a global fixed coordinate frame

Direct contour error compensation for biaxial contouring con...

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World Congress on Intelligent control and Automation (WCICA)

作者： Jiangzhao Yang Zexiang Li Hong Wang Yunjiang Lou Zhili Long Division of Control and Mechatronics Engineering Shenzhen Graduate School Harbin Institute of Technology Shenzhen China Department of Electronic and Computer Engineering Hong Kong University of Science and Technology Kowloon Hong Kong China

In the tasks of contour following, two important issues are required to be concerned. They are the real-time contour error estimation and compensation. Recent research shows that the accuracy of real-time contour error estimation can be improved by the approach of circular approximation. However, in such an approach, the estimated contour error is calculated from the artificial moving coordinate frame and has to be transformed back to the fixed coordinate frame for compensation. In this paper, an approach to estimate and compensate the real-time contour error based on the global fixed coordinate frame is proposed. In this method, the real-time contour error can be obtained from the tracking error decomposition to the global fixed coordinate frame via a projection map. Based on this estimation, direct contour error compensation will be performed with respect to the global fixed coordinate frame through modifying the reference position inputs. Experiments show that the estimation accuracy of the direct tracking error decomposition is the same as that of the circular estimation and the tracking performance of the contouring system is evidently improved after the compensation.

关键词： Approximation methods Real time systems Estimation Error analysis Error compensation Accuracy control systems

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On validation of the safety analysis of modern railway systems

On validation of the safety analysis of modern railway syste...

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IEEE International Conference on Service Operations and Logistics, and Informatics, SOLI

作者： Oleg Lisagor Linling Sun Tim Kelly Chao Liu Ru Niu High Integrity Systems Engineering Group Department of Computer Science University of York UK Key State Laboratory of Railway Traffic Control & Safety Beijing Jiaotong University China

Safety analysis is a key activity for the development of railway transportation systems. The analysis is used not only to determine whether new systems do not expose the general public to unduly high levels of risks, but also to inform the development process itself through identification and allocation of appropriate requirements. Whilst inadequate and inaccurate safety analysis may have potentially catastrophic consequences, it is rarely validated in practice. This paper presents a case for validation of safety analysis of the railway systems along with a technical approach to such validation. The approach is based on the concept of Failure Injection and the Lightweight Refinement relation. The paper further argues that the safety analysis validation should be embedded in a wider uncertainty management framework and shows how this can be made consistent with the spirit of the existing safety standards of the railway domain.

关键词： Safety Europe

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Bilateral Teleoperation control Without Velocity Measurements

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IFAC Proceedings Volumes 2011年第1期44卷 332-337页

作者： Emmanuel Nuño Luis Basañez Guillermo Obregón-Pulido Gualberto Solís-Perales Department of Computer Science. CUCEI. University of Guadalajara. Guadalajara Mexico Institute of Industrial and Control Engineering. Technical University of Catalonia. Barcelona Spain Electronics Department. CUCEI. University of Guadalajara. Guadalajara Mexico

Abstract This paper presents two controllers for a nonlinear bilateral teleoperation system that do not rely on velocity measurements. Under the reasonable assumptions that the human operator and the environment define passive maps from force to velocity, both controllers can ensure boundedness of velocities and position error. Moreover, if the human and environment forces are bounded, one of the controllers ensure velocity synchronization and the other velocity convergence to zero. Simulations, comparing the performance on free motion and interacting with a stiff wall, support the performance of the reported schemes.

关键词： Bilateral teleoperation Euler-Lagrange systems Lyapunov stability robot control

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Adaptive disassembly sequence control by using mobile robots and system information

Adaptive disassembly sequence control by using mobile robots...

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International Conference on System Theory, control, and Computing (ICSTCC)

作者： A. Radaschin A. Filipescu V. Minzu E. Minca Control Systems Department of Automation and Electical Engineering University Dunarea de Jos of Galati Galati Romania Department of Automation and Electical Engineering University Dunarea de Jos of Galati Romania Department of Automation Computer Science and Electrical Engineering Valahia University of Targoviste Targoviste Romania

Assembly and disassembly processes are similar from the viewpoint of automation. Assembly process is more or less a “classical” subject; disassembly process is more a quite new field. Flexible system are very important issue in the current industry when disassembling and recycling tasks have to be performed. These tasks can be performed by a human operator or by a robot system. In this paper an autonomous robot with manipulator system perform the required task for different operation. This system takes into consideration the necessary task to perform the disassembly of a component using robots synchronization with flexible line process. The proposed algorithm is to distribute the task among the robot and flexible line and takes into consideration the characteristics of each sequence that needs to be followed to perform the required disassembly of the product. The proposed system is validated by experiments using several types of components.

关键词： Planning Assembly Automation Plastics Mobile robots Educational institutions

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Vision system for mobile robots for tracking moving targets, based on robot motion and stereo vision information

Vision system for mobile robots for tracking moving targets,...

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IEEE/SICE International Symposium on System Integration

作者： Tae-Il Kim Wook Bahn Changhun Lee Tae-jae Lee Muhammad Muneeb Shaikh Kwang-soo Kim Automation and Systems Research Institute (ASRI) and School of Electrical Engineering and Computer Science Seoul National University Seoul South Korea Department of Control and Instrumentation Engineering Hanbat National University Daejeon South Korea

This paper presents a vision-tracking for mobile robots, which tracks a moving target based on robot motion and stereo vision information. The proposed system controls pan and tilt actuators attached to a stereo camera, using the data from a gyroscope, robot wheel encoders, pan and tilt actuator encoders, and the stereo camera. Using this proposed system, the stereo camera always faces the moving target. The developed system calculates the angles of the pan and tilt actuators by estimating the relative position of the target with respect to the position of the robot. The developed system estimates the target position using the robot motion information and the stereo vision information. The movement of the robot is modeled as the transformation of the frame, which consists of a rotation and a translation. The developed system calculates the rotation using 3-axis gyroscope data and the translation using robot wheel encoder data. The proposed system measures the position of the target relative to the robot, combining the encoder data of pan and tilt actuators and the disparity map of the stereo vision. The inevitable mismatch of the data, which occurs from the asynchrony of the multiple sensors, is prevented by the proposed system, which compensates for the communication latency and the computation time. The experimental results show that the developed system achieves excellent tracking performance in several motion scenarios, including combinations of straights and curves and climbing of slopes.

关键词： Cameras Mobile robots Robot vision systems Actuators Instruction sets

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