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Desenvolvimento de sistemas de controle via rede (NCS) para aplicações em redes com protocolo CAN; Development of networked control systems for applications in CAN-based networks

Godoy, Eduardo Paciência
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 21/03/2011 PT
Relevância na Pesquisa
65.82%
Sistema de controle via rede (NCS) é um sistema de controle distribuído onde os sensores, atuadores e controladores estão alocados fisicamente em locais separados e são conectados através de uma rede de comunicação industrial. O NCS representa a evolução das arquiteturas de controle em rede, fornecendo maior modularidade e descentralização do controle, facilidade de diagnóstico e manutenção e menor custo. O desafio no desenvolvimento de um NCS é contornar os efeitos degenerativos causados por fatores que afetam o seu desempenho e estabilidade. Entre estes fatores estão o período de amostragem dos sinais, a perda de informações transmitidas na rede e os atrasos de comunicação. Buscando superar este desafio, este trabalho apresenta o desenvolvimento de NCS para aplicações em redes CAN baseado no uso da simulação e na proposta de uma estratégia de controle. A utilização de ferramentas de simulação de NCS, selecionadas através de um estudo comparativo e qualitativo, permitiu analisar o impacto de fatores degenerativos no desempenho de controle e estabilidade de NCS. Essa análise por simulação permitiu evidenciar o período de amostragem como o fator de maior influência para o projeto de NCS em redes CAN. Para superar o problema do período de amostragem...

Model-based adaptive control of acetate concentration during the production of recombinant proteins with E. coli

Rocha, I.; Ferreira, E. C.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2003 ENG
Relevância na Pesquisa
65.81%
A model-based adaptive linearizing control law was derived for the regulation of the acetate concentration during the fed-batch fermentation of recombinant proteins with high cell density culture of Escherichia coli growing on glucose. An unstructured model for the growth was applied to the major metabolic pathways: oxidative growth on glucose, fermentative growth on glucose, oxidative growth on acetate, and maintenance. A model order reduction method was used to allow the development of the control algorithm without the knowledge of the kinetic structure being necessary. The non-linear model was subjected to transformations in order to obtain a linear behaviour for the control loop when a non-linear control is applied. The control law requires on-line acetate and carbon dioxide and oxygen transfer rates measurements. Acetate measurements are achieved with a developed Flow Injection Analysis (FIA) physical-chemical method. The gas transfer rates are calculated from gas analysis data obtained with a Mass Spectrometer (MS) connected to the exhaust gas line of the fermenter and also to the inlet aeration line. These calculations, as well as the implementation of the control law were performed through a MATLAB script embedded in a LABView program that also acquired data from the FIA system and other relevant state variables from the fermenter Digital Control Unit. Copyright 2002 IFAC; Agência de Inovação - PROTEXPRESS.; Fundação para a Ciência e a Tecnologia (FCT) – PRAXIS XXI/BD/16961/98.

Cross-Layer Adaptive Feedback Scheduling of Wireless Control Systems

Xia, Feng; Ma, Longhua; Peng, Chen; Sun, Youxian; Dong, Jinxiang
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
Publicado em 15/07/2008 EN
Relevância na Pesquisa
65.87%
There is a trend towards using wireless technologies in networked control systems. However, the adverse properties of the radio channels make it difficult to design and implement control systems in wireless environments. To attack the uncertainty in available communication resources in wireless control systems closed over WLAN, a cross-layer adaptive feedback scheduling (CLAFS) scheme is developed, which takes advantage of the co-design of control and wireless communications. By exploiting cross-layer design, CLAFS adjusts the sampling periods of control systems at the application layer based on information about deadline miss ratio and transmission rate from the physical layer. Within the framework of feedback scheduling, the control performance is maximized through controlling the deadline miss ratio. Key design parameters of the feedback scheduler are adapted to dynamic changes in the channel condition. An event-driven invocation mechanism for the feedback scheduler is also developed. Simulation results show that the proposed approach is efficient in dealing with channel capacity variations and noise interference, thus providing an enabling technology for control over WLAN.

Self-tuning regulator design for adaptive control of aircraft wing/store flutter

Fonte: Laboratory for Information and Decision Systems, Massachusetts Institute of Technology Publicador: Laboratory for Information and Decision Systems, Massachusetts Institute of Technology
Formato: p. 1014-1023; 1189723 bytes; application/pdf
ENG
Relevância na Pesquisa
75.77%
by Timothy L. Johnson, Charles A. Harvey, Gunter Stein.; "October, 1982."; Bibliography: p. 1022-1023.; Contract F33615-77OC-3096 NASA/Ames Grant NGL-22-009-124

A frequency-domain estimation for use in adaptive control systems

Fonte: Laboratory for Information and Decision Systems, Massachusetts Institute of Technology] Publicador: Laboratory for Information and Decision Systems, Massachusetts Institute of Technology]
Formato: 7 leaves; 882441 bytes; application/pdf
ENG
Relevância na Pesquisa
75.67%
by Richard O. LaMaire ... [et al.].; "Proc. American Control Conference, Minneapolis, MN, June 1987."; Bibliography: leaf 7.; Partially supported by the NASA Ames and Langley Research Centers under grant NASA/NAG-2-297 Partially supported by the Office of Naval Research under contract ONR/N00014-82-K-0502 (NR 606-0003) Partially supported by the National Science Foundation under grant NSF/ECS-8210960

Adaptive fault-tolerant tracking control of near-space vehicle using Takagi-Sugeno fuzzy models

Jiang, B.; Gao, Z.; Shi, P.; Xu, Y.
Fonte: IEEE-Inst Electrical Electronics Engineers Inc Publicador: IEEE-Inst Electrical Electronics Engineers Inc
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
65.8%
Based on the adaptive-control technique, this paper deals with the problem of fault-tolerant tracking control for near-space-vehicle (NSV) attitude dynamics. First, Takagi-Sugeno (T-S) fuzzy models are used to describe the NSV attitude dynamics; then, an actuator-fault model is developed. Next, an adaptive fault-tolerant tracking-control scheme is proposed based on the online estimation of actuator faults, in which a compensation control term is introduced in order to reduce the effect of actuator faults. Compared with some existing results of fault-tolerant control (FTC) in nonlinear systems, the technique presented in this paper is not dependent on fault detection and isolation (FDI) mechanism and is easy to implement in aerospace-engineering applications. Finally, simulation results are given to illustrate the effectiveness and potential of the proposed FTC scheme.; Bin Jiang, Zhifeng Gao, Peng Shi, and Yufei Xu

Adaptive observer based fault diagnosis for satellite attitude control systems

Wang, J.; Jiang, B.; Shi, P.
Fonte: ICIC International Publicador: ICIC International
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
Relevância na Pesquisa
65.84%
This paper presents a novel fault diagnosis method for satellite attitude control systems. Under Lipschitz condition on the nonlinear part of such systems, a nonlinear adaptive observer is for the actuator fault diagnosis. Moreover, the convergence and its speed of the developed algorithm are also investigated. Finally, simulation results have been included to demonstrate the feasibility and effectiveness of the new designed techniques.; Jianfei Wang, Bin Jiang and Peng Shi

A novel model-free adaptive control design for multivariable industrial processes

Xu, D.; Jiang, B.; Shi, P.
Fonte: IEEE Publicador: IEEE
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
65.87%
In this paper, a multiple adaptive observer-based strategy is proposed for the control of multi-input multi-output nonlinear processes using input/output (I/O) data. In the strategy, the pseudopartial-derivative parameter matrix of compact form dynamic linearization is estimated by a multiple adaptive observer, which is used to dynamically linearize a nonlinear system. Then, the proposed data-driven model-free-adaptive-control algorithm is only based on the online identified multiobserver models derived from the I/O data of the controlled plants, and Lyapunov-based stability analysis is used to ensure that all signals of the close-loop control system are bounded. A numerical example and a Wood/Berry distillation column example are provided to show that the proposed control algorithm has a very reliable tracking ability and a satisfactory robustness to disturbances and process dynamics variations.; Dezhi Xu, Bin Jiang and Peng Shi

Adaptive Identification of Nonlinear Systems

LEHRER, DEVON HAROLD
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
65.88%
This work presents three techniques for parameter identification for nonlinear systems. The methods presented are expanded from those presented in Adetola and Guay [3, 4, 5] and are intended to improve the performance of existing adaptive control systems. The first two methods exactly recover open-loop system parameters once a defined convergence condition is met. In either case, the true parameters are identified when the regressor matrix is of full rank and can be inverted. The third case uses a novel method developed in Adetola and Guay [5] to define a parameter uncertainty set. The uncertainty set is periodically updated to shrink around the true value of the parameters. Each method is shown to be applicable to a large class of linearly parameterized nonlinear discrete-time system. In each case, parameter convergence is guaranteed subject to an appropriate convergence condition, which has been related to a classical persistence of excitation condition. The effectiveness of the methods is demonstrated using a simulation example. The application of the uncertainty set technique to nonlinearly parameterized systems constitutes the main contribution of the thesis. The parameter uncertainty set method is generalized to the problem of adaptive estimation in nonlinearly parameterized systems...

On Designing Self-Adaptive Software Systems; Diseño de software autoadaptativo

Villegas Machado, Norha Milena; Müller, Hausi A.; Tamura Morimitsu, Gabriel
Fonte: Universidad Icesi; Facultad de Ingeniería Publicador: Universidad Icesi; Facultad de Ingeniería
Tipo: article; Artículo Formato: PDF; Electrónico
SPA
Relevância na Pesquisa
65.93%
Ante condiciones cambiantes del entorno, los sistemas autoadaptativos pueden modificarse a sí mismos para controlar la satisfacción de sus requerimientos en tiempo de ejecución. Durante el siglo pasado los sistemas de retroalimentación fueron importantes modelos para controlar el comportamiento dinámico de sistemas mecánicos, eléctricos, de fluidos y químicos, en sus respectivos campos de la ingeniería. Más recientemente fueron adoptados para diseñar software autoadaptativo. No obstante, lograr mapeos coherentes y explícitos consistentemente entre las arquitecturas de software adaptativo y los elementos de sistemas de retroalimentación es aún un reto abierto. Este artículo, sobre un modelo de referencia propuesto con ese propósito, discute aspectos clave del diseño de software autoadaptativo, en que los elementos de sistemas de retroalimentación se definen explícitamente como componentes de primer nivel en su arquitectura. Adicionalmente, ilustra la aplicación de este modelo de referencia a un ejemplo real de software adaptativo. El artículo ofrece a los ingenieros de software un punto de referencia para iniciar el diseño de software autoadaptativo.; Self-adaptive systems modify themselves at run-time in order to control the satisfaction of their requirements under changing environmental conditions. Over the past century...

Simplified robust adaptive control of a class of time-varying chaotic systems

Duarte Mermoud, Manuel Armando; Travieso Torres, Juan C.; Beltrán Maturana, Nicolás; Estrada, Jorge L.
Fonte: EMERALD GROUP PUBLISHING LIMITED Publicador: EMERALD GROUP PUBLISHING LIMITED
Tipo: Artículo de revista
EN
Relevância na Pesquisa
65.93%
Purpose - To develop a simplified robust control scheme for a class of nonlinear time-varying uncertain chaotic systems. Design/methodology/approach - By means of input-to-state stability theory, a new robust adaptive control scheme is designed, which is simpler than the one proposed by Li et al. and applicable to a larger class of nonlinear systems. Only one parameter is adjusted in the controller and the scheme assures that all the signals remain bounded. The behavior of the proposed control scheme is also analyzed through simulations on the Rossler system. Findings - By adjusting only one parameter in the controller and imposing only one mild assumption on the time-varying parameters, the proposed control algorithm assures that all the signal remain bounded and that the state of the original system will follow a desired trajectory defined either by the trajectory and its first time derivative, or given by a reference model.. Research limitations/implications - The results are limited to a particular class of nonlinear systems where the dimension of the input vector is equal to the order of the system (dimension of the state vector). Practical implications - The main advantage of the proposed method is that the modification introduced leads to a substantially simpler adaptive robust controller whose practical implementation will be easier. Originality/value - The contribution of the proposed method is in the simplification of the control algorithm applied to a class of...

Multiple model adaptive control with safe switching

Anderson, Brian; Brinsmead, Thomas; Liberzon, Daniel; Morse, A
Fonte: John Wiley & Sons Inc Publicador: John Wiley & Sons Inc
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
65.89%
The purpose of this paper is to marry the two concepts of multiple model adaptive control and safe adaptive control. In its simplest form, multiple model adaptive control involves a supervisor switching among one of a finite number of controllers as more

Adaptive Control Design under Structured Model Information Limitation: A Cost-Biased Maximum-Likelihood Approach

Farokhi, Farhad; Johansson, Karl H.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
75.87%
Networked control strategies based on limited information about the plant model usually results in worse closed-loop performance than optimal centralized control with full plant model information. Recently, this fact has been established by utilizing the concept of competitive ratio, which is defined as the worst case ratio of the cost of a control design with limited model information to the cost of the optimal control design with full model information. We show that an adaptive controller, inspired by a controller proposed by Campi and Kumar, with limited plant model information, asymptotically achieves the closed-loop performance of the optimal centralized controller with full model information for almost any plant. Therefore, there exists, at least, one adaptive control design strategy with limited plant model information that can achieve a competitive ratio equal to one. The plant model considered in the paper belongs to a compact set of stochastic linear time-invariant systems and the closed loop performance measure is the ergodic mean of a quadratic function of the state and control input. We illustrate the applicability of the results numerically on a vehicle platooning problem.; Comment: Improved presentation, Fixed typos

Collocated Adaptive Control of Underactuated Mechanical Systems

Romano, Francesco; Pucci, Daniele; Nori, Francesco
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 20/05/2014
Relevância na Pesquisa
65.9%
Collocated adaptive control of underactuated systems is still a main concern for the control community, all the more so because the collocated dynamics is no longer linear with respect to the constant base parameters. This work extends and encompasses the well known adaptive control result for fully actuated mechanical systems to the underactuated case. The key point is the introduction of a fictitious control input that allows us to consider the complete system dynamics, which is assumed to be linear with respect to the base parameters. Local stability and convergence of time varying reference trajectories for the collocated dynamics are demonstrated by using Lyapunov and Barbalat arguments. Simulation and experimental results on a two-link manipulator verify the soundness of the proposed approach.

When is a Parameterized Controller Suitable for Adaptive Control?

Ortega, Romeo; Panteley, Elena
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 30/05/2014
Relevância na Pesquisa
65.79%
In this paper we investigate when a parameterized controller, designed for a plant depending on unknown parameters, admits a realization which is independent of the parameters. It is argued that adaptation is unnecessary for this class of parameterized controllers. We prove that standard model reference controllers (state and output--feedback) for linear time invariant systems with a filter at the plant input admit a parameter independent realization. Although the addition of such a filter is of questionable interest, our result formally, and unquestionably, establishes the deleterious effect of such a modification, which has been widely publicized in the control literature under the name L1-adaptive control.

Adaptive Zero Reaction Motion Control for Free-Floating Space Manipulators

Xu, Shuanfeng; Wang, Hanlei; Zhang, Duzhou; Yang, Baohua
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
65.92%
This paper investigates adaptive zero reaction motion control for free-floating space manipulators with uncertain kinematics and dynamics. The challenge in deriving the adaptive reaction null-space (RNS) based control scheme is that it is difficult to obtain a linear expression, which is the basis of the adaptive control. The main contribution of this paper is that we skillfully obtain such a linear expression, based on which, an adaptive version of the RNS-based controller (referred to as the adaptive zero reaction motion controller in the sequel) is developed at the velocity level, taking into account both the kinematic and dynamic uncertainties. It is shown that the proposed controller achieves both the spacecraft attitude regulation and end-effector trajectory tracking. The performance of the proposed adaptive controller is shown by numerical simulations with a planar 3-DOF (degree-of-freedom) space manipulator.; Comment: 17 pages, 9 figures, revised for more rigorously presenting the proof and for improving the presentation, highlighting the contribution, and correcting some typos based on the reviewers' and AE's comments from IEEE Transactions on Aerospace and Electronic Systems

Model Reference Adaptive Control of Systems with Gain Scheduled Reference Models

Pakmehr, Mehrdad; Yucelen, Tansel
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 14/03/2014
Relevância na Pesquisa
95.98%
Firstly, a new state feedback model reference adaptive control approach is developed for uncertain systems with gain scheduled reference models in a multi-input multi-output (MIMO) setting. Specifically, adaptive state feedback for output tracking control problem of MIMO nonlinear systems is studied and gain scheduled reference model system is used for generating desired state trajectories. Using convex optimization tools, a common Lyapunov matrix is computed for multiple linearizations near equilibrium and non-equilibrium points of the nonlinear closed loop gain scheduled reference system. This approach guarantees stability of the closed-loop gain scheduled system. Adaptive state feedback control scheme is then developed, and its stability is proven. The resulting closed-loop system is shown to have bounded solutions with bounded tracking error, with the proposed stable gain scheduled reference model. Secondly, the developed control approach is improved for systems with constraints on the control inputs. The resulting closed-loop system is shown to have bounded solutions with bounded tracking error. Sufficient conditions for ultimate boundedness of the closed-loop system are derived. A semi-global stability result is proved with respect to the level of saturation for open-loop unstable plants while the stability result is shown to be global for open-loop stable plants. Thirdly...

Cross-Layer Adaptive Feedback Scheduling of Wireless Control Systems

Xia, Feng; Ma, Longhua; Peng, Chen; Sun, Youxian; Dong, Jinxiang
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 29/09/2008
Relevância na Pesquisa
65.87%
There is a trend towards using wireless technologies in networked control systems. However, the adverse properties of the radio channels make it difficult to design and implement control systems in wireless environments. To attack the uncertainty in available communication resources in wireless control systems closed over WLAN, a cross-layer adaptive feedback scheduling (CLAFS) scheme is developed, which takes advantage of the co-design of control and wireless communications. By exploiting cross-layer design, CLAFS adjusts the sampling periods of control systems at the application layer based on information about deadline miss ratio and transmission rate from the physical layer. Within the framework of feedback scheduling, the control performance is maximized through controlling the deadline miss ratio. Key design parameters of the feedback scheduler are adapted to dynamic changes in the channel condition. An event-driven invocation mechanism for the feedback scheduler is also developed. Simulation results show that the proposed approach is efficient in dealing with channel capacity variations and noise interference, thus providing an enabling technology for control over WLAN.; Comment: 17 pages, 12 figures; Open Access at http://www.mdpi.org/sensors/papers/s8074265.pdf

Autonomous Sensor Path Planning and Control for Active Information Gathering

Lu, Wenjie
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2014
Relevância na Pesquisa
65.88%

Sensor path planning and control refer to the problems of determining the trajectory and feedback control law that best support sensing objectives, such as monitoring, detection, classification, and tracking. Many autonomous systems developed, for example, to conduct environmental monitoring, search-and-rescue operations, demining, or surveillance, consist of a mobile vehicle instrumented with a suite of proprioceptive and exteroceptive sensors characterized by a bounded field-of-view (FOV) and a performance that is highly dependent on target and environmental conditions and, thus, on the vehicle position and orientation relative to the target and the environment. As a result, the sensor performance can be significantly improved by planning the vehicle motion and attitude in concert with the measurement sequence. This dissertation develops a general and systematic approach for deriving information-driven path planning and control methods that maximize the expected utility of the sensor measurements subject to the vehicle kinodynamic constraints.

The approach is used to develop three path planning and control methods: the information potential method (IP) for integrated path planning and control, the optimized coverage planning based on the Dirichlet process-Gaussian process (DP-GP) expected Kullback-Leibler (KL) divergence...

Learning From Neural Control

Wang, Cong; Hill, David
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
65.88%
One of the amazing successes of biological systems is their ability to "learn by doing" and so adapt to their environment. In this paper, first, a deterministic learning mechanism is presented, by which an appropriately designed adaptive neural controller is capable of learning closed-loop system dynamics during tracking control to a periodic reference orbit. Among various neural network (NN) architectures, the localized radial basis function (RBF) network is employed. A property of persistence of excitation (PE) for RBF networks is established, and a partial PE condition of closed-loop signals, i.e., the PE condition of a regression subvector constructed out of the RBFs along a periodic state trajectory, is proven to be satisfied. Accurate NN approximation for closed-loop system dynamics is achieved in a local region along the periodic state trajectory, and a learning ability is implemented during a closed-loop feedback control process. Second, based on the deterministic learning mechanism, a neural learning control scheme is proposed which can effectively recall and reuse the learned knowledge to achieve closed-loop stability and improved control performance. The significance of this paper is that the presented deterministic learning mechanism and the neural learning control scheme provide elementary components toward the development of a biologically-plausible learning and control methodology. Simulation studies are included to demonstrate the effectiveness of the approach.