In this paper, we present a nonlinear H ∞ control technique for the bilateral teleoperation of a nonlinear master-slave system. The proposed controller guarantees robust stability in the presence of uncertainty in op...
In this paper, we present a nonlinear H ∞ control technique for the bilateral teleoperation of a nonlinear master-slave system. The proposed controller guarantees robust stability in the presence of uncertainty in operator and environment impedances. The guidelines to include nonlinear intervening tool between master and slave robot are suggested. The proposed technique enables adjusting weighting of position and force tracking error functions for both amplitude and frequency domain. To solve the corresponding partial differential equation, called HJI, an approximation method based on Taylor series expansion of the solution is used. A numerical simulation demonstrates that the linear controller tends to instability in contact tasks while the third order approximated nonlinear controller yields desired performance.
A new Terahertz photodetector based on Electromagnetically Induced Transparency (EIT) is proposed. In the terahertz range (low energy signal) the limiting point is dark current. Dark current determines the signal-nois...
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In this paper, design of an ultra high-resolution, compact and tunable optical displacement sensor for optomechatronical systems is presented. In this proposal nanophotonic principles are used to develop displacement ...
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Rate adaptation is the determination of the optimal data transmission rate most appropriate for current wireless channel conditions. It consists of assessing channel conditions and accordingly adjusting the rate. Rate...
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Rate adaptation is the determination of the optimal data transmission rate most appropriate for current wireless channel conditions. It consists of assessing channel conditions and accordingly adjusting the rate. Rate adaptation is fairly challenging due to wild channel conditions fluctuations. In the last decade, rate adaptation for IEEE 802.11 networks has been extensively investigated. This paper presents a comprehensive and detailed study of the advances of rate adaptation schemes proposed for IEEE 802.11 networks, and summarizes their characteristics. We also categorize these rate adaptation schemes based on their support of loss differentiation and their methods to sense the channel conditions. Then, this paper compares the performance of three representative schemes through simulations. Finally, open issues for rate adaptation are raised.
Given a wireless network and a graph modelling the node connection topology, we address the problem of fault diagnosis of nodes. When the external point of access to network information is at a lower layer of the ISO/...
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Given a wireless network and a graph modelling the node connection topology, we address the problem of fault diagnosis of nodes. When the external point of access to network information is at a lower layer of the ISO/OSI protocol stack, the problem is trivial. However, as often occurs, a user is able to access the network at the application layer : this implies that the available observation of the network status is considerably restricted, and solving the diagnosis problem is not trivial. In this paper, we state necessary and sufficient conditions for being able to detect which node is faulty, and propose a diagnosis algorithm on the basis of diagnosability definitions and theoretical studies developed for timed and hybrid automata in the computer science community.
software architecture and visual programming languages both share a common goal of abstraction. software architecture tries to present a high level over view of the over all system design. This high level view can be ...
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The purpose of this pilot study was to explore the feasibility of using hand drawn images to identify symbol components for incorporation into warning symbol design software. This software will use an interactive evol...
The purpose of this pilot study was to explore the feasibility of using hand drawn images to identify symbol components for incorporation into warning symbol design software. This software will use an interactive evolutionary computation (IEC) algorithm to generate and evolve symbols mathematically described by a set of numerical parameters. Therefore, participants (N = 100) ages 19–43 (x = 23.2) were recruited to determine these symbol design parameters. Participants were invited to hand draw warning symbols for three referents: fall from elevation, hearing protection, and hazardous atmosphere. A panel of design engineers determined 27 attributes were present in the fall from elevation, 19 in the hearing protection, and 25 in the hazardous atmosphere images. A direct clustering algorithm was used to determine which attributes, or symbol parameters, were most commonly present or conspicuously absent among the clustered image families. For the fall from elevation, hearing protection and hazardous atmosphere referents, the clustering algorithm identified six, four and four symbol parameters, respectively, primarily responsible for distinguishing one drawn symbol from another. Thus, these parameters will be included as evolvable genes in the IEC software.
Many routing protocols exist for mobile ad hoc *** select the most appropriate protocol,evaluation of candidate protocols must be performed with respect to a specific operating environment,which is not an easy ***,sel...
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Many routing protocols exist for mobile ad hoc *** select the most appropriate protocol,evaluation of candidate protocols must be performed with respect to a specific operating environment,which is not an easy ***,selecting the best protocol can be a key factor in system behavior,determining whether the system successfully satisfies application *** of the relevant research in this area relies on simulation studies or empirical analysis to select a routing protocol,requiring an infeasible amount of time and resources for the approaches to be used in real-time decision *** this paper we describe work toward analytically expressing protocol performance metrics in terms of environment-,protocol,and application-dependent *** work provides a foundation for adaptive protocol suites that will eventually enable an integrated context-aware communication paradigm.
An autonomous flight control system for small size unmanned helicopter Sky-explorer based on dynamics model at Shanghai Jiaotong University is presented. At first, a mathematical model for small size helicopter based ...
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An autonomous flight control system for small size unmanned helicopter Sky-explorer based on dynamics model at Shanghai Jiaotong University is presented. At first, a mathematical model for small size helicopter based on Newton's mechanics is introduced. It is cited from Technical University of Berlin. Then the flight attitude controller based on this dynamics model for small size unmanned helicopter is presented. After that, a control algorithm-model and trajectory based controller named MTC by the author is introduced. It is a simple but effective control algorithm for a double integrator. Based on MTC, a flight position controller is achieved without overshooting. The MTC block is also used to achieve the translation velocity control and no stopping multi-way-point flight control by guide-position method along any defined curve course. The simulation result and the performance in real flight experiment demonstrate that the controller presented in this paper is a successful and practical flight controller for small size helicopter with a stiff main rotor.
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