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$\mathcal{L}_{2}$-Gain Analysis for a Class of Hybrid Systems With Applications to Reset and Event-Triggered control: A Lifting Approach

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IEEE Transactions on automatic control 2016年第10期61卷 2766-2781页

作者： W. P. M. H. Heemels G. E. Dullerud A. R. Teel Control System Technology Group Department of Mechanical Engineering Eindhoven University of Technology Eindhoven The Netherlands Mechanical Science and Engineering Department and Coordinated Science Laboratory University of Illinois Urbana IL USA Department of Electrical and Computer Engineering University of California Santa Barbara CA USA

In this paper we study the stability and L 2 -gain properties of a class of hybrid systems that exhibit linear flow dynamics, periodic time-triggered jumps and arbitrary nonlinear jump maps. This class of hybrid systems is relevant for a broad range of applications including periodic event-triggered control, sampled-data reset control, sampled-data saturated control, and certain networked control systems with scheduling protocols. For this class of continuous-time hybrid systems we provide new stability and L 2 -gain analysis methods. Inspired by ideas from lifting we show that the stability and the contractivity in L 2 -sense (meaning that the L 2 -gain is smaller than 1) of the continuous-time hybrid system is equivalent to the stability and the contractivity in L 2 -sense (meaning that the ℓ 2 -gain is smaller than 1) of an appropriate discrete-time nonlinear system. These new characterizations generalize earlier (more conservative) conditions provided in the literature. We show via a reset control example and an event-triggered control application, for which stability and contractivity in L 2 -sense is the same as stability and contractivity in ℓ 2 -sense of a discrete-time piecewise linear system, that the new conditions are significantly less conservative than the existing ones in the literature. Moreover, we show that the existing conditions can be reinterpreted as a conservative ℓ 2 -gain analysis of a discretetime piecewise linear system based on common quadratic storage/Lyapunov functions. These new insights are obtained by the adopted lifting-based perspective on this problem, which leads to computable L 2 -gain (and thus L 2 -gain) conditions, despite the fact that the linearity assumption, which is usually needed in the lifting literature, is not satisfied.

关键词： Stability analysis control systems Numerical stability Nonlinear systems Linear systems Linearity Electronic mail

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Corrigendum: Dielectric cross-shaped-resonator-based metasurface for vortex beam generation at mid-IR and THz wavelengths (Nanophotonics (2019) 8:7 (1263–1270) DOI: 10.1515/nanoph-2019-0112)

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Nanophotonics 2019年

作者： Dharmavarapu, Raghu Izumi, Ken-ichi Katayama, Ikufumi Ng, Soon Hock Vongsvivut, Jitraporn Tobin, Mark J. Kuchmizhak, Aleksandr Nishijima, Yoshiaki Bhattacharya, Shanti Juodkazis, Saulius Centre for NEMS and Nanophotonics (CNNP) Department of Electrical Engineering Indian Institute of Technology Madras Chennai 600036 India Centre for Micro-Photonics Faculty of Science Engineering and Technology Swinburne University of Technology Hawthorn VIC 3122 Australia Melbourne Centre for Nanofabrication ANFF 151 Wellington Road Clayton VIC 3168 Australia Physics Department Yokohama National University 79-5 Tokiwadai Hodogaya-ku Yokohama 240-8501 Japan Infrared Microspectroscopy Beamline Australian Synchrotron Clayton VIC 3168 Australia Institute of Automation and Control Processes Far Eastern Branch Russian Academy of Sciences Vladivostok 690041 Russia Far Eastern Federal University Vladivostok 690090 Russia Department of Electrical and Computer Engineering Graduate School of Engineering Yokohama National University 79-5 Tokiwadai Hodogaya-ku Yokohama 240-8501 Japan Institute of Advanced Sciences Yokohama National University 79-5 Tokiwadai Hodogaya-ku Yokohama 240-8501 Japan Tokyo Tech World Research Hub Initiative (WRHI) School of Materials and Chemical Technology Tokyo Institute of Technology 2-12-1 Ookayama Meguro-ku Tokyo 152-8550 Japan

There was a mistake in the grant number used in the recently published paper (DOI: https://***/10.1515/ nanoph-2019-0112. Published Online: 2019-07-09). The text should read: A.K. is grateful for support via the Russian science Foundation (grant no. 17-19-01325), and R.D. thanks the IIT Madras-Swinburne joint PhD program. © 2019 De Gruyter. All rights reserved.

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MTS2: Many task scheduling simulator 29

MTS2: Many task scheduling simulator

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29th European Conference on Modelling and Simulation, ECMS 2015

作者： Stratulat, Adrian Oncioiu, Raluca Pop, Florin Dobre, Ciprian Computer Science Department Faculty of Automatic Control and Computers University Politehnica of Bucharest Romania

ISBN: (纸本)9780993244001

The Many Task Computing paradigm was first introduced by loan Raicu and could be described shortly as solving a large number of tasks with short time executions (i.e. seconds to minutes long) that are data intensive. We propose MTS2: Many Task Scheduling Simulator that can be used for a broad range of simulations-after each simulation one can visualize the results. The purpose of MTS2 framework is to simulate events that happen inside a cluster in order to experimentally check or validate various classes of scheduling algorithms. Our event-based simulator provides the building blocks that can be used to implement mathematical models for simulations and it is designed to be extensible, fast and scalable. For the purpose of scheduling algorithm evaluation, the performance is critical: we will study the asymptotic behaviour of some scheduling algorithms under extreme conditions. We will show that MTS2 can be used in various scheduling algorithms and performs better than SimMatrix on a quad core machine, regarding the time per task: 7 microseconds compared to 100 microseconds for simulations with one node and less than 0.5 microseconds with MTS2 for simulations with more than 64 nodes. © ECMS Valen M. Mladenov, Petia Georgieva, Grisha Spasov, Galidiya Petrova (Editors).

关键词： Scheduling algorithms

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Dynamic Modularity Approach to Adaptive Inner/Outer Loop control of Robotic Systems

Dynamic Modularity Approach to Adaptive Inner/Outer Loop Con...

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第35届中国控制会议

作者： Hanlei Wang Wei Ren Chien Chern Cheah Yongchun Xie Science and Technology on Space Intelligent Control Laboratory Beijing Institute of Control Engineering Department of Electrical and Computer Engineering University of California School of Electrical and Electronic Engineering Nanyang Technological University

ISBN: (纸本)9781509009107

Modern applications of robotics typically involve a robot control system with an inner PI(proportional-integral) or PID(proportional-integral-derivative) control loop and an outer user-specified control loop. The existing outer loop controllers,however, do not take into consideration the dynamic effects of robots and their effectiveness relies on the ad hoc assumption that the inner PI or PID control loop is fast enough, and other torque-based control algorithms cannot be implemented in robotics with closed architecture(i.e., the torque control loop is closed). In this paper, we propose a dynamic modularity approach to resolve this issue, and a class of adaptive outer loop control schemes is proposed for robotic systems with an inner/outer loop structure and their role is to generate joint velocity and position commands for the low-level joint servoing loop. Without relying on the ad hoc assumption that the joint servoing is fast enough or the modification of the low-level joint controller structure, we rigorously show that the proposed outer loop controllers can ensure the stability and convergence of the closed-loop robotic system. We also propose the outer loop version of the standard Slotine and Li adaptive controller in joint space, and a promising conclusion may be that most torque-based adaptive controllers for robots can be redesigned to fit the inner/outer loop structure, by using the adaptively scaled dynamic compensation and the new definition of the joint velocity command. Simulation results are provided to show the performance of the proposed adaptive outer loop controllers, using a three-DOF(degree-of-freedom) manipulator.

关键词： Inner/outer loop adaptive control dynamic modularity approach robotics

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Model reduction for linear parameter varying systems using scaled diagonal dominance

Model reduction for linear parameter varying systems using s...

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American control Conference

作者： Harald Pfifer Tamas Peni Aerospace and Engineering Mechanics Department University of Minnesota USA Systems and Control Laboratory of Institute for Computer Science and Control (MTA-SZTAKI) Budapest Hungary

ISBN: (纸本)9781467386838

A model-reduction method for linear, parameter-varying (LPV) systems based on parameter-varying balanced realizations is proposed. In general, this requires the solution of a large set of linear matrix inequalities, leading to numerical issues and high computational cost. It has been recognized recently that semidefinite optimization problems (SDP) can be cast into second order cone programs (SOCP) by replacing the positive definiteness constraints with stronger, scaled diagonal dominance conditions. Since the scalability of SOCP solvers is much better than that of the SDPs, the new formulation allows solving large scale model reduction problems more efficiently. A numerical example is provided to demonstrate the efficiency of the approach.

关键词： Reduced order systems Symmetric matrices Mathematical model Linear systems Linear matrix inequalities controllability Observability

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Damage detection in metallic plates using d36 piezoelectric phased arrays 8

Damage detection in metallic plates using d36 piezoelectric ...

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8th European Workshop on Structural Health Monitoring, EWSHM 2016

作者： Wang, Wentao Lynch, Jerome P. Li, Hui Key Lab of Structures Dynamic Behavior and Control Ministry of Education Harbin Institute of Technology Harbin150090 China Department of Civil and Environmental Engineering University of Michigan Ann ArborMI48109-2125 United States Department of Electrical Engineering and Computer Science University of Michigan Ann ArborMI48109-2125 United States

ISBN: (纸本)9781510827936

Recently, d36-type piezoelectric wafers derived from lead magnesium niobate-lead titanate (PMN-PT) single crystal materials have been proposed for elastic wave generation in thinwalled structures. In contrast to traditional d31 piezoelectric materials which generate symmetric and anti-symmetric Lamb waves, d36 introduces these same Lamb waves plus an inplane shear horizontal (SH) wave. Based on guided wave theory, the SH0 wave mode is nondispersive which may find many advantages uses in structural health monitoring. To detect and localize damage (e.g., cracks, corrosion) in thin walled structures, a phased array of d36- type piezoelectric wafers is proposed. To validate the proposed phase array, extensive experiments have been conducted using an aluminum plate with four d36 PMN-PT piezoelectric wafers surface bonded. The d36 phased array is shown capable of accurately detecting the location of local damage in the plate. Good detection accuracy is observed indicating that this proposed methodology has the potential to provide an effective identification of damage in metallic thin walled structures.

关键词： Damage detection

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Model Error Modeling and Stochastic Embedding

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IFAC-PapersOnLine 2015年第28期48卷 75-79页

作者： Ljung, Lennart Goodwin, Graham C. Agüero, Juan C. Chen, Tianshi Div. of Automatic Control Linköping University Sweden School of Electrical Engineering and Computer Science The University of Newcastle CallaghanNSW 2308 Australia

To estimate a model of useful complexity for control design, at the same time as having a good insight into its reliability is a central issue in system identification, in particular for identification for control. Basically one can think of a (simpler) design model and a (more complex and exible) error model. These concepts are discussed in terms of model error modeling and stochastic embedding in a framework that allows the error model to vary over time. It is then of interest to estimate a probabilistic description of this error model. This can be accomplished by estimating parameters that describe the pdf of the errors. In this contribution explicit expressions for the likelihood function for these parameters are derived by marginalization over the error model, in case this is a linear regression. © 2015

关键词： Stochastic models Errors Stochastic systems Design modeling Empirical Bayes Error quantification Estimating parameters Identification for control Likelihood functions Model errors Probabilistic descriptions

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Dynamic and recursive oil-reservoir proxy using Elman neural networks

Dynamic and recursive oil-reservoir proxy using Elman neural...

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2016 IEEE ANDESCON, ANDESCON 2016

作者： Tupac, Yvan Talavera, Alvaro Rivero, Cristian Rodriguez Computer Science School Universidad Católica San Pablo Arequipa Peru Department of Engineering Universidad Del Pacífico Lima Peru Math Research Laboratory Applied to Control Universidad Nacional de Córdoba Córdoba Argentina

ISBN: (纸本)9781509025312

In this work, a reservoir simulation approximation model (proxy) based on recurrent artificial neural networks is proposed. This model is intended to obtain rates of oil, gas and water production at time t+1 from the respective production rates, average pressure and water cut at t time and the well operation points to be applied in t + 1. Also, this model is able to follow the dynamics of the reservoir system applying online learning from real production observed values. Also, this model allows perform fast and accurate production forecasting for several steps using a recursive mechanism. This model will be inserted into an oil-production control tool to find the optimal operation conditions within a forecast horizon. The obtained outcomes over the approximation tests indicate the methodology is adequate to perform production forecasts. © 2016 IEEE.

关键词： Production control

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Improved computation of individual ZPD in a distance learning system

Improved computation of individual ZPD in a distance learnin...

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International Conference on Information Technology Based Higher Education and Training, ITHET

作者： Sara De Cristofano Maria De Marsico Andrea Sterbini Marco Temperini Department of Computer Science Sapienza University of Rome Rome Italy Department of Computer Control and Management Engineering Antonio Ruberti Sapienza University of Rome Rome Italy

ISBN: (纸本)9781509007790

This paper builds upon theoretical studies in the field of social constructivism. Lev Vygotsky is considered one of the greatest representatives of this research line, with his theory of the Zone of Proximal Development (ZPD). Our work aims at integrating this concept in the practice of a computer-assisted learning system. For each learner, the system stores a model summarizing the current Student Knowledge (SK). Each educational activity is specified through the deployed content, the skills required to tackle it, and those acquired, and is further annotated by the effort estimated for the task. The latter may change from one student to another, given the already achieved competence. A suitable weighting of the robustness (certainty) of student's skills, stored in SK, and their combination are used to verify the inclusion of a learning activity in the student's ZPD. With respect to our previous work, the algorithm for the calculation of the ZPD of the individual student has been optimized, by enhancing the certainty weighting policy, and a graphical display of the ZPD has been added. Thanks to the latter, the student can get a clear vision of the learning paths that he/she can presently tackle. This both facilitates the educational process, and helps developing the metacognitive ability self-assessment.

关键词： Problem-solving computer aided instruction Collaboration Context Electronic learning Learning systems

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Fault diagnosis, failure prognosis and fault tolerant control of aerospace/unmanned aerial systems

Fault diagnosis, failure prognosis and fault tolerant contro...

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Mediterranean Conference on control and Automation (MED)

作者： George Vachtsevanos George Georgoulas George Nikolakopoulos School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta GA USA Control Engineering Group Department of Computer Science Luleå University of Technology Luleå Sweden

ISBN: (纸本)9781467383479

Fault-tolerant control and operation of complex unmanned and aircraft systems is an emerging technology intended to provide the designer and operator with flexibility, interoperability, sustainment and reliability under changing operational requirements or mission profiles. Moreover, it is intended to reconfigure online hardware and software to maintain the operational integrity of the system in the event of contingencies (fault/failure modes). This paper presents an hierarchical architecture that uses available sensor information, fault isolation, failure prognosis, system restructuring and controller reconfiguration. The fault tolerant control framework relies on prognostic information to reconfigure system components and preserve the operational integrity of the aircraft. The hierarchical structure starts at the lowest component level and migrates to the middle system/subsystem level ending with the final mission level. We illustrate the methodology using an electro-mechanical actuator (EMA).

关键词： Prognostics and health management Fault diagnosis Aircraft Feature extraction Fault tolerant control computer architecture Measurement

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