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THE APPROXIMATION FUNCTION OF BRIDGE DECK VIBRATION DERIVED FROM THE MEASURED EIGENMODES

INTERNATIONAL JOURNAL OF APPLIED MATHEMATICS AND COMPUTER SCIENCE 2017年第4期27卷 799-814页

作者： Sokol, Milan Komornikova, Magdalena Bacigal, Tomas Rodriguez, Miguel X. Slovak Univ Technol Bratislava Fac Civil Engn Dept Struct Mech Radlinskeho 11 SK-81005 Bratislava Slovakia Slovak Univ Technol Bratislava Fac Civil Engn Dept Math Radlinskeho 11 SK-81005 Bratislava Slovakia Monterrey Inst Technol & Higher Educ Sch Engn & Sci Campus PueblaVa Atlixcayotl 2301 Reserva Terr Atlixcayotl 72453 Puebla Mexico

This article deals with a method of how to acquire approximate displacement vibration functions. Input values are discrete, experimentally obtained mode shapes. A new improved approximation method based on the modal vibrations of the deck is derived using the least-squares method. An alternative approach to be employed in this paper is to approximate the displacement vibration function by a sum of sine functions whose periodicity is determined by spectral analysis adapted for non-uniformly sampled data and where the parameters of scale and phase are estimated as usual by the least-squares method. Moreover, this periodic component is supplemented by a cubic regression spline (fitted on its residuals) that captures individual displacements between piers. The statistical evaluation of the stiffness parameter is performed using more vertical modes obtained from experimental results. The previous method (Sokol and Flesch, 2005), which was derived for near the pier areas, has been enhanced to the whole length of the bridge. The experimental data describing the mode shapes are not appropriate for direct use. Especially the higher derivatives calculated from these data are very sensitive to data precision.

关键词： eigenmode approximation eigenmode derivatives regression spline spectral analysis distributed parameter system

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Long Time Prediction of Uncertain systems Using Singular Perturbation

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INTERNATIONAL JOURNAL OF UNCERTAINTY FUZZINESS AND KNOWLEDGE-BASED systemS 2017年第5期25卷 707-721页

作者： Harati, Ehsan Noubari, Hossein Ahmadi Univ Tehran Elect & Comp Engn Dept Enghelab Ave Tehran Iran Univ British Columbia Elect & Comp Engn Dept Vancouver BC Canada

This paper considers the problem of long time prediction of uncertain dynamic systems. Spectral methods such as polynomial chaos expansion (PCE) provides a suitable alternative for classical Monte Carlo method with lower computational load. However, polynomial chaos expansion has a major drawback of long time integration error. In this paper, we will apply singular perturbation (SP) method for reducing long time integra tion error. Using SP the accuracy of long time predictions are improved with comparable computational load. We will apply SP to illustrative exemplify problems to show effectiveness of our approach. Moreover, we will illustrate application of SP together with a model order reduction tool to reduce long time integration error as applied to distributed parameter.

关键词： Uncertainty quantification polynomial chaos expansion singular perturbation distributed parameter system discrete empirical interpolation

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Nonlinear observation in fuel cell systems: A comparison between disturbance estimation and High-Order Sliding-Mode techniques

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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 2016年第43期41卷 19737-19748页

作者： Luna, Julio Usai, Elio Husar, Attila Serra, Maria CSIC UPC Inst Robot & Informat Ind C Llorens & Artigas 4-6 Barcelona 08028 Spain Univ Cagliari DIEE I-09123 Cagliari Italy

This paper compares two Nonlinear distributed parameter Observers (NDPO) for the observation of a Proton Exchange Membrane Fuel Cell (PEMFC). Both NDPOs are based on the discretisation of distributed parameters models and they are used to estimate the state profile of gas concentrations in the anode and cathode gas channels of the PEMFC, giving detailed information about the internal conditions of the system. The reaction and water transport flow rates from the membrane to the channels are uncertainties of the observation problem and they are estimated throughout all the length of the PEMFC without the use of additional sensors. The first observation approach is a Nonlinear Disturbance Observer (NDOB) for the estimation of the disturbances in the NDPO. In the second approach, a novel implementation of a High-Order Sliding-Mode (HOSM) observer is developed to estimate the true value of the states as well as the reaction terms. The proposed observers are tested and compared through a simulation example at different operating points and their performance and robustness is analysed over a given case study, the New European Driving Cycle. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

关键词： PEMFC distributed parameter system Nonlinear observer Disturbance observer Sliding-mode

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distributed control of a class of flexible mechanical systems with global constraint

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INTERNATIONAL JOURNAL OF CONTROL 2016年第1期89卷 128-139页

作者： He, Wei Yang, Chuan Meng, Tingting Sun, Changyin Univ Sci & Technol Beijing Sch Automat & Elect Engn Beijing 100083 Peoples R China Univ Elect Sci & Technol China Sch Automat Engn Chengdu 611731 Peoples R China

In this paper, the constrained problem is investigated for both flexible string model and Euler-Bernoulli beam model with the tip payload, based on an infinite dimensional generalisation of a distributed control method. The control objectives are to develop the control law so that the motion of flexible mechanical systems can track a desired reference signal, and ensure that the string or beam remain in a constrained space. We prove that, with the proposed control, the tracking error is exponentially stable without violation of the constraint. The proof of convergence is based on an Integral-Barrier Lyapunov Function (IBLF), and extensive simulations are provided to illustrate the performance of the control system.

关键词： distributed control flexible structures distributed parameter system integral-Barrier Lyapunov function global constraint

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Fuzzy guaranteed cost sampled-data control of nonlinear systems coupled with a scalar reaction -diffusion process

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FUZZY SETS AND systemS 2016年第0期302卷 121-142页

作者： Wang, Jun-Wei Li, Han-Xiong Wu, Huai-Ning Univ Sci & Technol Beijing Sch Automat & Elect Engn Beijing 100083 Peoples R China City Univ Hong Kong Dept Syst Engn & Engn Management Tat Chee Ave Kowloon Hong Kong Peoples R China Cent S Univ State Key Lab High Performance Complex Mfg Changsha 410083 Hunan Peoples R China Beijing Univ Aeronaut & Astronaut Beihang Univ Sch Automat Sci & Elect Engn Sci & Technol Aircraft Control Lab Beijing 100191 Peoples R China

A fuzzy guaranteed cost sampled-data control problem is addressed in this paper for a class of nonlinear coupled systems of an n-dimensional lumped parameter system modeled by ordinary differential equation (ODE) with a scalar reaction diffusion process represented by parabolic partial differential equation (PDE). A Takagi Sugeno (T-S) fuzzy coupled ODE PDE model is initially proposed to accurately represent the nonlinear coupled ODE PDE system. Based on the T-S fuzzy coupled ODE PDE model, a fuzzy sampled-data controller is subsequently developed via the Lyapunov's direct method to not only locally exponentially stabilize the nonlinear coupled system, but also provide an upper bound of the given cost function. Moreover, a suboptimal fuzzy sampled-data control design is also addressed in the sense of minimizing the upper bound of the cost function. The main contribution of this study lies in that a new parameterized linear matrix inequality (LMI) technique is proposed to reduce the conservativeness of the method, and an LMI-based fuzzy suboptimal sampled-data control design is developed for the nonlinear coupled ODE PDE system based on this parameterized LMI technique. Simulation results on the sampled-data control of hypersonic rocket car are provided to illustrate the effectiveness and merit of the design method. (C) 2015 Elsevier B.V. All rights reserved.

关键词： Fuzzy control Sampled-data control Lumped parameter system distributed parameter system Linear matrix inequalities (LMIs)

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Approximate controllability of infinite dimensional system with internal damping dependent on fractional powers of system operator

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IET CONTROL THEORY AND APPLICATIONS 2016年第18期10卷 2370-2377页

作者： Wyrwal, Janusz Silesian Tech Univ Inst Automat Control Akad 16 PL-44100 Gliwice Poland

In this study, a class of models governed by a second-order (in time) evolution differential equation with damping and positive definite, self-adjoint system operator is studied. Damping term has a special, but practically important, form of a finite sum of fractional powers of the system operator. This type of damping operator can be used to model a variety of physical phenomena related to dissipation of energy empirically observed in physical systems. It may be used to model dissipation mechanisms resulting from air damping, internal structural damping, internal viscous damping, etc. Using spectral theory of linear unbounded operators and semi-group theory necessary and sufficient conditions of approximate controllability for second order infinite dimensional system with damping are formulated and proved. Some important, from the practical point of view, remarks and comments are also provided. In particular, necessary condition for approximate controllability is formulated and discussed. Finally, an illustrative example related to approximate controllability of distributed parameter system described by the partial differential equation with higher order spatial differential operators is presented. The example refers to a system describing dynamical behaviour of damped Kirchhoff-Love plate. The study extends earlier results on approximate controllability of damped second-order abstract evolution dynamical systems.

关键词： controllability multidimensional systems distributed parameter systems partial differential equations damping damped second-order abstract evolution dynamical systems damped Kirchhoff–Love plate higher order spatial differential operators partial differential equation distributed parameter system semigroup theory linear unbounded operators spectral theory internal viscous damping internal structural damping air damping physical systems energy dissipation physical phenomena positive definite operator second-order evolution differential equation system operator fractional powers internal damping second order infinite dimensional system approximate controllability

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Nonlinear predictive control for durability enhancement and efficiency improvement in a fuel cell power system

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JOURNAL OF POWER SOURCES 2016年第0期328卷 250-261页

作者： Luna, Julio Jemei, Samir Yousfi-Steiner, Nadia Husar, Attila Serra, Maria Hissel, Daniel CSIC UPC Inst Robot & Informat Ind C Llorens i Artigas 4-6 Barcelona 08028 Spain Univ Bourgogne Franche Comte FEMTO ST UMR CNRS 6174 Besancon France FR CNRS 3539 FCLAB Belfort France LABEX ACT CNRS Besancon France

In this work, a nonlinear model predictive control (NMPC) strategy is proposed to improve the efficiency and enhance the durability of a proton exchange membrane fuel cell (PEMFC) power system. The PEMFC controller is based on a distributed parameters model that describes the nonlinear dynamics of the system, considering spatial variations along the gas channels. Parasitic power from different system auxiliaries is considered, including the main parasitic losses which are those of the compressor. A nonlinear observer is implemented, based on the discretised model of the PEMFC, to estimate the internal states. This information is included in the cost function of the controller to enhance the durability of the system by means of avoiding local starvation and inappropriate water vapour concentrations. Simulation results are presented to show the performance of the proposed controller over a given case study in an automotive application (New European Driving Cycle). With the aim of representing the most relevant phenomena that affects the PEMFC voltage, the simulation model includes a two-phase water model and the effects of liquid water on the catalyst active area. The control model is a simplified version that does not consider two-phase water dynamics. (C) 2016 Elsevier B.V. All rights reserved.

关键词： Proton exchange membrane fuel cell distributed parameter system Nonlinear observer Model predictive control Degradation Starvation

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USING DRINKING DATA AND PHARMACOKINETIC MODELING TO CALIBRATE TRANSPORT MODEL AND BLIND DECONVOLUTION BASED DATA ANALYSIS SOFTWARE FOR TRANSDERMAL ALCOHOL BIOSENSORS

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MATHEMATICAL BIOSCIENCES AND ENGINEERING 2016年第5期13卷 911-934页

作者： Dai, Zheng Rosen, I. G. Wang, Chuming Barnett, Nancy P. Luczak, Susan E. Univ Southern Calif Dept Math Los Angeles CA 90089 USA Brown Univ Sch Publ Hlth Providence RI 02912 USA Univ Southern Calif Dept Psychol Los Angeles CA 90089 USA

Alcohol researchers/clinicians have two ways to collect subject/patient field data, standard-drink self-report and the breath analyzer, neither of which is passive or accurate because active subject participation is required. Transdermal alcohol sensors have been developed to measure trans dermal alcohol concentration (TAC), but they are used primarily as abstinence monitors because converting TAC into more meaningful blood/breath alcohol concentration (BAC/BrAC) is difficult. In this paper, BAC/BrAC is estimated from TAC by first calibrating forward distributed parameter-based convolution models for ethanol transport from the blood through the skin using patient collected drinking data for a single drinking episode and a nonlinear pharmacokinetic metabolic absorption/elimination model to estimate BAC. TAC and estimated BAC are then used to fit the forward convolution filter. Nonlinear least squares with adjoint-based gradient computation are used to fit both models. Calibration results are compared with those obtained using BAC/BrAC from alcohol challenges and from standard, linear, metabolic absorption, and zero order kinetics-based elimination models, by considering peak BAC, time of peak, and area under the BAC curve. Our models (with population parameters) could be included in a smart phone app that makes it convenient for the subject/patient to enter drinking data for a single episode in the field.

关键词： Pharmacokinetic modeling Michaelis-Menten drinking diary transdermal alcohol sensor deconvolution distributed parameter system boundary input and output

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Boundary feedback stabilisation of a flexible robotic manipulator with constraint

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INTERNATIONAL JOURNAL OF CONTROL 2016年第3期89卷 635-651页

作者： He, Wei Sun, Chen Univ Sci & Technol Beijing Sch Automat & Elect Engn Beijing 100083 Peoples R China Univ Toronto Edward S Rogers Sr Dept Elect & Comp Engn Toronto ON M5S 1A1 Canada

In this paper, the flexible robotic manipulator is modelled as a distributed parameter system, represented by a group of partial differential equations and ordinary differential equations. Control is designed at the boundary of the robotic manipulator based on integral-barrier Lyapunov function to suppress the vibration of the elastic deflection and track the desired angular position. With the proposed boundary control, the manipulator can be driven to the desired set-point with angular position and elastic deflection stay under the former setting constraint. Uniformed boundedness of the closed-loop system under the unknown time-varying disturbance is achieved. Stability analysis of the closed-loop system is given by employing the Lyapunov stability theory. Simulation results illustrate the effectiveness of the proposed boundary controller for ensuring output constraint and suppressing vibrations.

关键词： Flexible robotic manipulator distributed parameter system vibration control boundary control flexible structure

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Characteristics-based model predictive control of selective catalytic reduction in diesel-powered vehicles

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JOURNAL OF PROCESS CONTROL 2016年 47卷 98-110页

作者： Pakravesh, H. Aksikas, I. Votsmeier, M. Dubijevic, S. Hayes, R. E. Forbes, F. Univ Alberta Dept Chem & Mat Engn Edmonton AB T6G 2M7 Canada Qatar Univ Dept Math Stat & Phys Doha Qatar Umicore AG & Co KG Hanau Germany

In heavy-duty diesel exhaust systems, selective catalytic reduction (SCR) is used to reduce NOx to nitrogen to meet environmental regulations. Diesel exhaust after-treatment involves a set of components that are best characterized as distributed parameter systems. Thus, the optimal ammonia dosage in the SCR is an important and challenging problem in diesel exhaust treatment. In this work, we propose a method to synthesize an optimal controller for the SCR section of the diesel exhaust after-treatment system, which is based on a system model consisting of coupled hyperbolic and parabolic partial differential equations (PDEs). This results in a boundary control problem;where the control objectives are to reduce the amount of NOx emissions and ammonia slip to the fullest extent possible using the inlet concentration of ammonia as the manipulated variable and assuming that the concentrations of nitric oxide and nitrogen dioxide and ammonia, are measured at the SCR inlet and outlet. The proposed method combines the method of characteristics, spectral decomposition and the model predictive control (MPC) approach. For performance comparison purposes, the open-loop dynamic optimization problem is solved via Direct transcription (DT) to compute the upper performance limit for the optimal SCR problem. The results show that the proposed approach is able to achieve a very high level of control performance in terms of NO and ammonia slip reduction. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Selective catalytic reduction Model predictive control Method of characteristics Spectral decomposition Hyperbolic PDEs Parabolic PDEs distributed parameter system

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