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Genetic Fuzzy + PI Path Tracking Control of a Nonholonomic Mobile Robot

电子学报(英文版) 2011年第1期20卷 31-34页

作者： CAO Zhengcai ZHAO Yingtao WU Qidi College of Information Science and Technology Beijing University of Chemical Technology Beijing China The Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai China

A mobile robot is one of the well-known nonholonomic systems. The genetic fuzzy + PI path track- ing control applied to a mobile robot is presented. The pro- posed controller composes of two fuzzy + PI controllers which are employed to control the angular velocity to- gether, and one fuzzy + PI controller that is utilized to adjust the speed of mobile robot solely. Moreover, the fuzzy controller is designed to track reference path in ap- proaching phase and PI controller is operated to diminish the tracking error in stable phase. In order to obtain bet- ter tracking performance, Genetic algorithm (GA) is used to optimize controller parameters. Finally, computer sim- ulation results are given to illustrate the effectiveness of the proposed control scheme.

关键词：模糊PI控制器移动机器人机器人控制非完整系统路径跟踪遗传算法模糊控制器控制器参数

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Multicast Capacity Scaling Laws for Multihop Cognitive Networks

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IEEE Transactions on Mobile computing 2012年第11期11卷 1627-1639页

作者： Cheng Wang Shaojie Tang Xiang-Yang Li Changjun Jiang Key Laboratory of Embedded System and Service Computing Building of Electronics and Information Engineering Ministry of Education Shanghai China Department of Computer Science and Engineering University of Tongji China Department of Computer Science Illinois Institute of Technology Chicago IL USA Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing China Department of Computer Science and Engineering University of Tongji Shanghai China

In this paper, we study multicast capacity for cognitive networks. We consider the cognitive network model consisting of two overlapping ad hoc networks, called the primary ad hoc network (PaN) and secondary ad hoc network (SaN), respectively. PaN and SaN operate on the same space and spectrum. For PaN (or SaN, respectively), we assume that primary (or secondary, respectively) nodes are placed according to a Poisson point process of intensity n (or m, respectively) over a unit square region. We randomly choose n s (or m s , respectively) nodes as the sources of multicast sessions in PaN (or SaN, respectively), and for each primary source vp (or secondary source v s , respectively), we pick uniformly at random nd primary nodes (or md secondary nodes, respectively) as the destinations of v p (or v s , respectively). Above all, we assume that PaN can adopt the optimal protocol in terms of the throughput. Our main work is to design the multicast strategy for SaN by which the optimal throughput can be achieved, without any negative impact on the throughput for PaN in order sense. Depending on nd and n, we choose the optimal one for PaN from two strategies called percolation strategy and connectivity strategy, respectively. Subsequently, we design the corresponding throughput-optimal strategy for SaN. We derive the regimes in terms of n, n d , m, and m d in which the upper bounds on multicast capacities for PaN and SaN can be achieved simultaneously. Unicast and broadcast capacities for the cognitive network can be derived by our results as the special cases by letting n d = 1 (or m d = 1) and n d = n - 1 (or m d = m - 1), respectively, which enhances the generality of this work.

关键词： Throughput Ad hoc networks Road transportation Slabs Routing Lattices Mobile computing

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Maximally permissive control of flexible manufacturing systems with fewest disjunctive constraints

Maximally permissive control of flexible manufacturing syste...

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International Conference on Advanced Mechatronic systems (ICAMechS)

作者： YuFeng Chen MengChu Zhou XiaoOu Li School of Electro-Mechanical Engineering Xidian University Xi'an China Key Laboratory of Embedded System and Service Computing Ministry of Education University of Tongji Shanghai China Department of Electrical and Computer Engineering New Jersey Institute of Technology Newark NJ USA Departamento de Computacion CINVESTAVIPN Mexico Distrito Federal Mexico

For Petri net models whose legal reachability spaces are non-convex, one cannot optimally control them by the conjunctions of linear constraints. This work proposes a method to find a set of linear constraints such that each constraint can forbid all first-met bad markings and every legal marking satisfies at least one constraint. Then, the disjunctions of the obtained constraints can make all legal markings reachable and forbid all first-met bad markings, i.e., the controlled net is live and maximally permissive. The work also develops an integer linear programming model to minimize the number of the constraints. Finally, an example is provided to illustrate the proposed method.

关键词： Law Optimal control Vectors Aerospace electronics Petri nets system recovery

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Image quality assessment using sparse representation in ICA domain

Image quality assessment using sparse representation in ICA ...

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Asia-Pacific Signal and Information Processing Association Annual Summit and Conference 2011, APSIPA ASC 2011

作者： Cheng, Cheng Wang, Hanli Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai 200092 China

A novel metric for full-reference image quality assessment (IQA) is proposed in this paper. Based on the sparse representation in independent component analysis (ICA) domain, the image basis is generated from natural images adaptively, which coincides with the characteristics of human vision system (HVS). In order to extract the feature vector, a hybrid norm optimization strategy is introduced for achieving more stable computational performances. The proposed IQA metric is calculated as a correlation coefficient between the two feature vectors from reference and distorted images, respectively. Experimental results on the LIVE Database Release 2 demonstrate that the proposed metric can achieve competitive performances as compared to the well-known structural similarity (SSIM) metric.

关键词： Independent component analysis

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Battery discharge characteristics of wireless sensors in building applications

Battery discharge characteristics of wireless sensors in bui...

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IEEE International Conference on Networking, Sensing and Control

作者： Wenqi Guo William M. Healy Meng Chu Zhou Department of Electrical and Computer Engineering New Jersey Institute of Technology Newark NJ USA National Institute for Standards and Technology Gaithersburg MD USA Key Laboratory of Embedded System and Service Computing Ministry of Education University of Tongji Shanghai China ECE Department New Jersey Institute of Technology Newark NJ USA

Sensor nodes in wireless networks often use batteries as their source of energy, but replacing or recharging exhausted batteries in a deployed network can be difficult and costly. Therefore, prolonging battery life becomes a principal objective in the design of wireless sensor networks (WSNs). There is little published data that quantitatively analyze a sensor node's lifetime under different operating conditions. This paper presents several experiments to quantify the impact of key wireless sensor network design and environmental parameters on battery performance. Our testbed consists of MicaZ motes, commercial alkaline batteries, and a suite of techniques for measuring battery performance. We evaluate known parameters, such as communication distance, working channel and operating power that play key roles in battery performance. Through extensive real battery discharge measurements, we expect our results to serve as a quantitative basis for future research in designing and implementing battery-efficient sensing applications and protocols.

关键词： Batteries Wireless sensor networks Discharges (electric) Sensor phenomena and characterization Battery charge measurement Voltage measurement

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Adaptively selecting working frequency to reduce disturbances in high frequency radar

Adaptively selecting working frequency to reduce disturbance...

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作者： Gui, R.Z. Key Laboratory of Embedded System and Service Computing Tongji University Ministry of Education Shanghai 200092 China

In high frequency radar, we should avoid noise disturbances in the radar's working-frequency segment. Moreover, the sidelobes of strong targets interfere with the detection of weak targets. A new method based on an adaptive selecting working-frequency is proposed. Frequency spectrum monitor is designed for selecting quiet frequency segment for the radar. Frequency spectrum monitor and the receiver of the radar are arranged to work according to special time periods respectively. So the radar can work in the frequency segments with lower noise disturbances. Moreover, there is no correlation between the noise and the useful echo signal, though the correlation between noises over very short time periods is strong, the noise data produced by frequency spectrum monitor can be exploited effectively Adjusting system parameters in real-time by adaptive methods can be utilized to reduce noise disturbances. Algorithm based on the properties of crosscorrelation between noise and target is exploited for suppressing sidelobe disturbances of strong targets. Lastly, the feasibility of the methods is verified by processing actual radar data.

关键词： Data handling

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Model checking cooperative multi-agent systems in BDI logic

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Journal of Information and Computational Science 2012年第5期9卷 1185-1194页

作者： Chen, Qingliang Su, Kaile Wu, Lijun Xu, Zhaocheng School of Electronics Engineering and Computer Science Peking University Beijing 100871 China Department of Computer Science Jinan University Guangzhou 510632 China Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai China Institute for Integrated and Intelligent Systems Griffith University Brisbane Australia School of Computer Science and Engineering University of Electronic Science and Technology of China Chengdu China

Traditional temporal logics such as LTL (Linear Temporal Logic) and CTL (Computation Tree Logic) have shown tremendous success in specifying and verifying hardware and software systems. However, this kind of logic can only model the dynamic behaviors for a single system, and fall short in capturing the joint and concurrent aspects in the composition of systems, such as the interactions and coordinations of agents in Multi-agent systems. Although ATL (Alternating-time Temporal Logic) can solve the problem to a certain extent, by preceding the temporal operators with a selective path quantifier, to specify that the interactions between entities inside the system can make sure that there is a strategy to reach a certain state, it can not formalize the rational mental attitudes of the agents such as the Belief, Desire and Intention (BDI) which plays an essential role in decision making during cooperation with other agents. This paper will investigate this problem by proposing a logic of ATLBDI (Alternating-time Temporal Logic of Belief Desire and Intention) and discuss the algorithmic issues such as model checking algorithms and the computational complexity, along with examples to show its effectiveness. We conclude that model checking for ATLBDI is completely tractable and is in PTIME-Complete, which is quite an optimistic and promising result for further applications. © 2012 by Binary Information Press.

关键词： Multi agent systems

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Dynamic Walking of AIBO with Hopf Oscillators

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Chinese Journal of Mechanical Engineering 2011年第4期24卷 612-617页

作者： ZHANG Jiaqi TOMIZUKA Masayoshi CHEN Qijun LIU Chengju College of Electronic Information and Engineering Tongji University Shanghai 201804 China College of Electronic Information andEngineering Tongji University Shanghai 201804 China The Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai 201804 China

More and more biological evidences have been found that neural networks in the spinal cord, referred to as ＂central pattern generators＂（CPGs）, govern locomotion. CPGs are capable of producing rhythmic movements, such as swimming, flying, and walking, even when isolated from the brain and sensory inputs. If we could build up any models that have similar functions as CPGs, it will be much easier to design better locomotion for robots. In this paper, a self-training environment is designed and through genetic algorithm （GA）, walking trajectories for every foot of AIBO are generated at first. With this acquired walking pattern, AIBO gets its fastest locomotion speed. Then, this walking pattern is taken as a reference to build CPGs with Hopf oscillators. By changing corresponding parameters, the frequencies and the amplitudes of CPGs＇ outputs can be adjusted online. The limit cycle behavior of Hopf oscillators ensures the online adjustment and the walking stability against perturbation as well. This property suggests a strong adaptive capacity to real environments for robots. At last, simulations are carried on in Webots and verify the proposed method.

关键词： central pattern generators（CPGs） Hopf Oscillators walking control AIBO Webots

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Automatic Web services composition algorithm based on optimal matching

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Journal of Central South University 2011年第4期18卷 1169-1177页

作者：王俊丽丁志军侯玉兵 Engineering Research Center for Enterprise Digital Technology Ministry of EducationTongji University Key Laboratory of Embedded System and Service Computing Ministry of EducationTongji University Shanghai Branch China Information Technology Designing and Consulting Institute

A novel layered method was proposed to solve the problem of Web services *** this method,services composition problem was formally transformed into the optimal matching problem of every layer,then optimal matching problem was modeled based on the hypergraph theory,and solved by computing the minimal transversals of the ***,two optimization algorithms were designed to discard some useless states at the intermediary steps of the composition *** effectiveness of the composition method was tested by a set of experiments,in addition,an example regarding the travel services composition was also *** experimental results show that this method not only can automatically generate composition tree whose leaf nodes correspond to services composition solutions,but also has better performance on execution time and solution quality by adopting two proposed optimization algorithms.

关键词： Web services services composition optimal matching hypergraph theory

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Asymptotic throughput for large-scale wireless networks with general node density

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Wireless Networks 2012年第5期19卷 559-575页

作者： Cheng Wang Changjun Jiang Xiang-Yang Li Yunhao Liu Department of Computer Science Tongji University Shanghai China Key Laboratory of Embedded System and Service Computing Ministry of Education Shanghai China The Tsinghua National Laboratory for Information Science and Technology (TNLIST) Department of Computer Science and Engineering Tongji University Shanghai China The Department of Computer Science Illinois Institute of Technology Chicago USA The TNLIST and School of Software Tsinghua University Beijing China CSE The Hong Kong University of Science and Technology Kowloon Hong Kong

We study the asymptotic throughput for a large-scale wireless ad hoc network consisting of n nodes under the generalized physical model. We directly compute the throughput of multicast sessions to unify the unicast and broadcast throughputs. We design two multicast schemes based on the so-called ordinary arterial road system and parallel arterial road system, respectively. Correspondingly, we derive the achievable multicast throughput by taking account of all possible cases of n s = ω(1) and 1 ≤ n d ≤ n − 1, rather than only the cases of $$n_s=\Uptheta(n)$$ as in most related works, where n s and n d denote the number of sessions and the number of destinations of each session, respectively. Furthermore, we consider the network with a general node density $$\lambda \in [1,n]$$ , while the models in most related works are either random dense network (RDN) or random extended network (REN) where the density is λ = n and λ = 1, respectively, which further enhances the generality of this work. Particularly, for the special case of our results by letting λ = 1 and $$n_s=\Uptheta(n)$$ , we show that for some regimes of n d , the multicast throughputs achieved by our schemes are better than those derived by the well-known percolation-based schemes.

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