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Automatic Control, IEEE Transactions on

Issue 2 • Date March 2008

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Displaying Results 1 - 25 of 30
  • Table of contents

    Publication Year: 2008 , Page(s): C1 - C2
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    Freely Available from IEEE
  • IEEE Transactions on Automatic Control publication information

    Publication Year: 2008 , Page(s): C2
    Save to Project icon | Request Permissions | PDF file iconPDF (36 KB)  
    Freely Available from IEEE
  • Scanning the issue

    Publication Year: 2008 , Page(s): 445 - 446
    Save to Project icon | Request Permissions | PDF file iconPDF (37 KB) |  | HTML iconHTML  
    Freely Available from IEEE
  • Modular Control of Discrete-Event Systems With Coalgebra

    Publication Year: 2008 , Page(s): 447 - 460
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (287 KB) |  | HTML iconHTML  

    Modular supervisory control of discrete-event systems, where the overall system is a synchronous (parallel) product of subsystems, is considered. The main results of this paper are formulations of sufficient conditions for the compatibility between the synchronous product and various operations stemming from supervisory control as supervised product and supremal controllable sublanguages. These results are generalized to the case of modules with partial observations: e.g., modular computation of supremal normal sublanguages is studied. Coalgebraic techniques based on the coinduction proof principle are used in our main results. Sufficient conditions are derived for modular to equal global control synthesis. An algorithmic procedure for checking the new conditions is proposed and the computational benefit of the modular approach is discussed and illustrated by comparing the time complexity of modular and monolithic computation. View full abstract»

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  • Adaptive Control and Robustness in the Gap Metric

    Publication Year: 2008 , Page(s): 461 - 478
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (349 KB) |  | HTML iconHTML  

    We consider the construction of adaptive controllers for minimum phase linear systems that achieve nonzero robustness margins in the sense of the gap metric. The gap perturbation margin may be more constrained for larger disturbances and for larger parametric uncertainties. Working in both and settings, and within the framework of the nonlinear gap metric, universal adaptive controllers are first given achieving stabilization for first-order nominal plants, and the results are then generalized to relative degree one nominal plants. A notion of a semiuniversal control design is introduced, which is the property that a bound on performance exists that is independent of the a priori known uncertainty level, and a characterization is given for when semiuniversal designs outperform the class of memoryless controllers and the class of linear time-invariant controllers. Robust semiuniversal adaptive control designs are given for nominal plants under the classical assumptions of adaptive control in both the and settings. The results are applied throughout to explicit classes of unmodeled dynamics including the Rohrs example. View full abstract»

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  • Optimal Strategies for Multiclass Job Scheduling on a Single Machine With Controllable Processing Times

    Publication Year: 2008 , Page(s): 479 - 495
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (434 KB) |  | HTML iconHTML  

    A particular scheduling problem over a single machine is considered. Jobs belong to different classes, and two jobs belonging to the same class are considered as completely equivalent. A sequence of due dates is specified for each class of jobs, and the serviced jobs, for each class, are assigned to the due dates according to the EDD rule. The service time of any job of a given class has to be selected within an interval of possible values (the highest possible one being the nominal service time). A deviation of the actual service time from the nominal value determines a cost that has a linear dependence on such a deviation. The cost function to be minimized is the sum of the total (weighted) tardiness cost and the overall service time deviation cost. The decision variables are those concerning job sequencing (taking into account the equivalence of jobs of the same class) and service times. In this paper, a solution to this problem is provided in terms of closed-loop strategies. View full abstract»

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  • The n th-Order Bias Optimality for Multichain Markov Decision Processes

    Publication Year: 2008 , Page(s): 496 - 508
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (232 KB) |  | HTML iconHTML  

    In this paper, we propose a new approach to the theory of finite multichain Markov decision processes (MDPs) with different performance optimization criteria. We first propose the concept of nth-order bias; then, using the average reward and bias difference formulas derived in this paper, we develop an optimization theory for finite MDPs that covers a complete spectrum from average optimality, bias optimality, to all high-order bias optimality, in a unified way. The approach is simple, direct, natural, and intuitive; it depends neither on Laurent series expansion nor on discounted MDPs. We also propose one-phase policy iteration algorithms for bias and high-order bias optimal policies, which are more efficient than the two-phase algorithms in the literature. Furthermore, we derive high-order bias optimality equations. This research is a part of our effort in developing sensitivity-based learning and optimization theory. View full abstract»

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  • Numerical Solutions for Stochastic Differential Games With Regime Switching

    Publication Year: 2008 , Page(s): 509 - 521
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (327 KB) |  | HTML iconHTML  

    This paper is concerned with numerical methods for stochastic differential games of regime-switching diffusions. Numerical methods using Markov chain approximation techniques are developed. A new proof of the existence of a saddle point for the stochastic differential game is provided. This new proof enables us to treat certain systems with nonseparable (in controls) structure. Convergence of the algorithms is derived by means of weak convergence methods. In addition, examples are also provided for demonstration purposes. View full abstract»

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  • Synthesis of Inference-Based Decentralized Control for Discrete Event Systems

    Publication Year: 2008 , Page(s): 522 - 534
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (275 KB) |  | HTML iconHTML  

    In our past work, we presented a framework for the decentralized control of discrete event systems involving inferencing over ambiguities, about the system state, of various local decision makers. Using the knowledge of the self-ambiguity and those of the others, each local control decision is tagged with a certain ambiguity level (level zero being the minimum and representing no ambiguity). A global control decision is taken to be a "winning" local control decision, i.e., one with a minimum ambiguity level. For the existence of a decentralized supervisor, so that for each controllable event the ambiguity levels of all winning disablement or enablement decisions are bounded by some number N (such a supervisor is termed N-inferring), the notion of N- inference-observability was introduced. When the given specification fails to satisfy the iV-inference-observability property, an iV-inferring supervisor achieving the entire specification does not exist. We first show that the class of iV-inference-observable sublanguages is not closed under union implying that the supremal N- inference-observable sublanguage need not exist. We next provide a technique for synthesizing an N -inferring decentralized supervisor that achieves an N -inference-observable sublanguage of the specification. The sublanguage achieved equals the specification language when the specification itself is iV-inference-observable. A formula for the synthesized sublanguage is also presented. For the special cases of N = 0 and N = 1, the proposed supervisor achieves the same language as those reported in [25], [31] (for N = 0) and [32] (for N = 1). The synthesized supervisor is parameterized by N (the parameter bounding the ambiguity level), and as N is increased, the supervisor becomes strictly more permissive in general. Thus, a user can choose N based on the degree of permissiveness and the degree of computational complexity desired. View full abstract»

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  • Decentralized Diagnosis of Stochastic Discrete Event Systems

    Publication Year: 2008 , Page(s): 535 - 546
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (271 KB) |  | HTML iconHTML  

    We investigate the decentralized diagnosis of stochastic discrete event systems (SDESs) by using multiple local stochastic diagnosers, each possessing its own sensors to deal with different information. We formalize the notions of decentralized diagnosis for SDESs by defining the concept of codiagnosability for stochastic automata, in which any communication among the local stochastic diagnosers or to any coordinators is not involved. These notions are weaker than the corresponding notions of decentralized diagnosis of classical DESs. A stochastic system being codiagnosable means that a fault can be detected by at least one local stochastic diagnoser within a finite delay. We construct a codiagnoser from a given stochastic system with a finite number of projections whose each diagnosis component uses the complete model of the system. We also deal with a number of basic properties of the codiagnoser. In particular, a necessary and sufficient condition of the codiagnosability for SDESs is presented, which generalizes the corresponding results of centralized diagnosis for SDESs. Also, we give a computing method in detail to check the codiagnosability of SDESs. As an application of our results, some examples are described. View full abstract»

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  • Decentralized Supervisory Control of Discrete-Event Systems Over Communication Networks

    Publication Year: 2008 , Page(s): 547 - 559
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (369 KB) |  | HTML iconHTML  

    In this paper, we investigate the problem of designing embedded decentralized discrete-event controllers over communication networks. It is assumed that there is a path between every pair of processes in the network. The control objective is specified by a prefix-closed language that is controllable and observable, but not coobservable. The paper is focused on communication among processes necessary to meet the control objective. As such, process models are left unspecified; it is only required that disabling any of the controllable events do not block communication among processes. Our findings support the idea that in the presence of ideal communication channels, the protocol design for noncoobservable specifications can be reduced to the synthesis of communicating decentralized supervisors, and we propose solutions for a restricted class of problems. The paper is concluded with a positive result for the case where channels are unreliable. View full abstract»

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  • On Evaluating SFM-Based Infinitesimal Perturbation Analysis Estimates From Discrete Event System Data

    Publication Year: 2008 , Page(s): 560 - 565
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (491 KB) |  | HTML iconHTML  

    This paper investigates the evaluation of infinitesimal perturbation analysis (IPA) estimates that have been derived based on a stochastic fluid model (SFM) using data observed from the sample path of a discrete event system (DES). First, we show that a straightforward implementation of the SFM-based IPA estimates may yield biased estimates when the data are obtained from the actual DES. Then, in order to better approximate the sample path of the DES, we propose a special case of SFM where the arrival and service processes are modeled by piecewise constant on/off sources. The proposed SFM violates some of the assumptions made in [1]-[4] , and, as a result, the sample derivatives no longer exist. However, using the proposed SFM, we obtain the left and right sided sample derivative estimates. As shown in this paper, the sided sample derivatives are much better in approximating the required derivatives compared to the straightforward implementation of the SFM-based IPA estimates. View full abstract»

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  • Stability Region Analysis Using Polynomial and Composite Polynomial Lyapunov Functions and Sum-of-Squares Programming

    Publication Year: 2008 , Page(s): 565 - 571
    Cited by:  Papers (47)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (662 KB) |  | HTML iconHTML  

    We propose using (bilinear) sum-of-squares programming for obtaining inner bounds of RoAs for dynamical systems with polynomial vector fields. We search for polynomial as well as composite Lyapunov functions comprised of pointwise maximums of polynomial functions. Results for several examples from the literature are presented using the proposed methods and the PENBMI solver. View full abstract»

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  • Realizations of Nonlinear Control Systems on Time Scales

    Publication Year: 2008 , Page(s): 571 - 575
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (141 KB) |  | HTML iconHTML  

    Nonlinear partially defined systems on an arbitrary unbounded time scale are studied. They include continuous-time and discrete-time systems. The main problem is to find necessary and sufficient conditions for an abstract input/output map to have a realization as a nonlinear system of a specific class on the time scale. The obtained results extend criteria of realizability of continuous-time polynomial systems. A simple construction of a realization is provided. View full abstract»

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  • A Discrete-Time Periodic Adaptive Control Approach for Time-Varying Parameters With Known Periodicity

    Publication Year: 2008 , Page(s): 575 - 581
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (341 KB) |  | HTML iconHTML  

    A periodic adaptive control approach is proposed for a class of nonlinear discrete-time systems with time-varying parametric uncertainties that are periodic, and the only prior knowledge is the periodicity. The new adaptive controller updates the parameters and the control signal periodically in a point-wise manner over one entire period, and in the sequel, achieves the asymptotic tracking convergence. The result is further extended to a scenario with mixed time-varying and time-invariant parameters, and a hybrid classical and a periodic adaptation law is proposed to handle the scenario more appropriately. The extension of the periodic adaptation to systems with unknown input gain, higher order dynamics, and tracking problems is also discussed. View full abstract»

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  • Monotonic Convergence of Iterative Learning Control for Uncertain Systems Using a Time-Varying Filter

    Publication Year: 2008 , Page(s): 582 - 585
    Cited by:  Papers (19)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (130 KB) |  | HTML iconHTML  

    Iterative learning control (ILC) is a learning technique used to improve the performance of systems that execute the same task multiple times. Learning transient behavior has emerged as an important topic in the design and analysis of ILC systems. In practice, the learning control is often low-pass filtered with a ldquoQ-filterrdquo to prevent transient growth, at the cost of performance. In this note, we consider linear time-invariant, discrete-time, single-input single-output systems, and convert frequency-domain uncertainty models to a time-domain representation for analysis. We then develop robust monotonic convergence conditions, which depend directly on the choice of the Q-filter and are independent of the nominal plant dynamics. This general result is then applied to a class of linear time-varying Q-filters that is particularly suited for precision motion control. View full abstract»

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  • Design and Analysis of a Novel {cal L}_1 Adaptive Control Architecture With Guaranteed Transient Performance

    Publication Year: 2008 , Page(s): 586 - 591
    Cited by:  Papers (48)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (382 KB) |  | HTML iconHTML  

    This paper presents a novel adaptive control architecture that adapts fast and ensures uniformly bounded transient response for system's both signals, input and output, simultaneously. This new architecture has a low-pass filter in the feedback loop and relies on the small-gain theorem for the proof of asymptotic stability. The tools from this paper can be used to develop a theoretically justified verification and validation framework for adaptive systems. Simulations illustrate the theoretical findings. View full abstract»

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  • Robust Feedback Control for a Class of Uncertain MIMO Nonlinear Systems

    Publication Year: 2008 , Page(s): 591 - 596
    Cited by:  Papers (16)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (803 KB) |  | HTML iconHTML  

    In this paper, a continuous feedback tracking controller is developed for a class of high-order multi-input multi-output (MIMO) nonlinear systems with an input gain matrix that has nonzero leading principal minors but can be nonsymmetric. Under the mild assumption that the signs of the leading minors of the control input gain matrix are known, the controller yields locally uniformly ultimately bounded (UUB) tracking while compensating for unstructured uncertainty in both the drift vector and the input matrix. First, a full-state feedback controller is designed based on limited assumptions on the structure of the system nonlinearities, and the singularity-free controller is proven to yield locally UUB tracking through a Lyapunov-based analysis. Then, it is shown that an output feedback control can be designed based on a high-gain observer. Simulation results are provided to illustrate the performance of the proposed control algorithm. View full abstract»

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  • Converging Coevolutionary Algorithm for Two-Person Zero-Sum Discounted Markov Games With Perfect Information

    Publication Year: 2008 , Page(s): 596 - 601
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (199 KB) |  | HTML iconHTML  

    This note proposes a novel population-based coevolutionary algorithm, called the ldquolocal-equilibrium-based coevolutionary algorithmrdquo (LECA), for solving infinite-horizon-discounted two-person zero-sum Markov games with perfect information. LECA ldquorandomizesrdquo a simplified variant of Raghavan and Syed's algorithm, which adapted Howard's policy improvement algorithm for solving Markov decision processes into a ldquonegotiation processrdquo algorithm between two players via a lexicographical search. LECA runs over relatively small sets of policies such that the negotiation process proceeds with the sets via ldquopolicy switching,rdquo rather than with the entire policy spaces of the players. The use of policy switching eliminates the action spaces manipulation in value iteration and policy iteration-type algorithms and derives a novel concept of ldquolocal equilibrium.rdquo With the concept incorporated into the LECA, a ldquolocalrdquo equilibrium policy pair is identified as an ldquoelitist,rdquo and kept in the next population, directing the LECA toward finding an equilibrium or a near-equilibrium policy pair. The algorithm is especially targeted to problems where the state space is small but the action spaces of the players are extremely large, and converges with probability one to an equilibrium policy pair for a given game. View full abstract»

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  • A Sharp Estimate for the Probability of Stability for Polynomials With Multilinear Uncertainty Structure

    Publication Year: 2008 , Page(s): 601 - 606
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (206 KB) |  | HTML iconHTML  

    This paper addresses the probability of stability for uncertain polynomials that have multilinear functions of real parameters as coefficients. We obtain an estimate for the probability of stability with respect to a class of admissible distributions. This estimate is ldquosharprdquo in the following sense: one obtains a probability of stability of unity when the bounds on the hypercube uncertainty bounding set are below the deterministic robustness radius obtained with the well-known mapping theorem. View full abstract»

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  • Nonquadratic Stabilization Conditions for a Class of Uncertain Nonlinear Discrete Time TS Fuzzy Models: A New Approach

    Publication Year: 2008 , Page(s): 606 - 611
    Cited by:  Papers (112)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (192 KB) |  | HTML iconHTML  

    The discrete-time uncertain nonlinear models are considered in a Takagi-Sugeno form and their stabilization is studied through a non- quadratic Lyapunov function. The classical conditions consider a one- sample variation, here, the main results are obtained considering k samples variation, i.e., Deltak V(x(t)) = V(x(t + k)) - V(x(t)). The results are shown to always include the classical cases, and several examples illustrate the effectiveness of the approach. View full abstract»

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  • Density Functions for Navigation-Function-Based Systems

    Publication Year: 2008 , Page(s): 612 - 617
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (189 KB) |  | HTML iconHTML  

    In this paper, we present a scheme for constructing density functions for systems that are almost globally asymptotically stable (i.e., systems for which all trajectories converge to an equilibrium except for a set of measure zero) using navigation functions (NFs). Although recently-proven converse theorems guarantee the existence of density functions for such systems, such results are only existential and the construction of a density function for almost globally asymptotically stable systems remains a challenging task. We show that for a specific class of dynamical systems that are defined based on an NF, a density function can be easily derived from the system's underlying NF. View full abstract»

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  • Output Feedback Control of Bilinear Systems via a Bilinear LTR Observer

    Publication Year: 2008 , Page(s): 617 - 621
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (131 KB) |  | HTML iconHTML  

    In the literature, most observer-based output feedback controls for bilinear systems are only applicable to open-loop (neutrally) stable systems. This paper proposes a new observer-based output feedback control that can be applied to open-loop unstable systems. The key component of the new control is an exponentially stable bilinear loop transfer recovery (LTR) observer that derives from the linear LTR observer. View full abstract»

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  • On Linear-Quadratic Stackelberg Games With Time Preference Rates

    Publication Year: 2008 , Page(s): 621 - 625
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (138 KB) |  | HTML iconHTML  

    This note deals with linear-quadratic Stackelberg differential games including time preference rates with an open-loop information structure. The properties of the characteristic matrix associated with the necessary conditions for a Stackelberg strategy are pointed out. It is shown that such a matrix exhibits a special symmetry property of its eigenvalues. Sufficient conditions to guarantee a predefined degree of stability are given based on the distribution of the eigenvalues in the complex plane. View full abstract»

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  • A Note on Marginal Stability of Switched Systems

    Publication Year: 2008 , Page(s): 625 - 631
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (265 KB) |  | HTML iconHTML  

    In this note, we present criteria for marginal stability and marginal instability of switched systems. For switched nonlinear systems, we prove that uniform stability is equivalent to the existence of a common weak Lyapunov function (CWLF) that is generally not continuous. For switched linear systems, we present a unified treatment for marginal stability and marginal instability for both continuous-time and discrete-time switched systems. In particular, we prove that any marginally stable system admits a norm as a CWLF. By exploiting the largest invariant set contained in a polyhedron, several insightful algebraic characteristics are revealed for marginal stability and marginal instability. View full abstract»

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Aims & Scope

In the IEEE Transactions on Automatic Control, the IEEE Control Systems Society publishes high-quality papers on the theory, design, and applications of control engineering.  Two types of contributions are regularly considered

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
P. J. Antsaklis
Dept. Electrical Engineering
University of Notre Dame