Notification:
We are currently experiencing intermittent issues impacting performance. We apologize for the inconvenience.
By Topic

Automatic Control, IEEE Transactions on

Issue 7 • Date July 2001

Filter Results

Displaying Results 1 - 25 of 25
  • Extending H//sub/spl infin// control to nonlinear systems [Book Review]

    Publication Year: 2001 , Page(s): 1172 - 1174
    Save to Project icon | Request Permissions | PDF file iconPDF (35 KB)  
    Freely Available from IEEE
  • Observer-based control of systems with slope-restricted nonlinearities

    Publication Year: 2001 , Page(s): 1146 - 1150
    Cited by:  Papers (94)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (172 KB) |  | HTML iconHTML  

    An observer design is presented which makes use of bounds on the slope of system nonlinearities. Necessary and sufficient conditions are derived for the feasibility of the design. A class of state feedback control laws are characterized which, when implemented with the observer states, ensure global asymptotic stability. One such certainty-equivalence design is illustrated on an active magnetic bearing example View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Stabilization of dynamical systems by adding a colored noise

    Publication Year: 2001 , Page(s): 1107 - 1111
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (188 KB) |  | HTML iconHTML  

    Stabilization of dynamics of a system has been of great concern to researchers and practitioners over the years. It is observed that the system is more viscous if one adds a noise in the system. In the present situation, the system is perturbed by a (multiplicative) noise and the stable/unstable behavior is examined. It is then observed that, one can stabilize or destabilize a large class of systems of ordinary differential equations (ODE) and stochastic differential equations (SDE) if a noise is carefully added View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Controlled invariance and feedback laws

    Publication Year: 2001 , Page(s): 1141 - 1146
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (172 KB) |  | HTML iconHTML  

    We consider controlled invariance for cones, translated cones, polyhedra and various special polyhedral structures. For any polyhedron, if controlled invariance occurs, then all and nothing but the admissible controls can be obtained by an inequative feedback controller. For each special polyhedral structure we compare this feedback controller against piecewise affine, linear and affine feedback controllers View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Asymptotic behavior of nonlinear networked control systems

    Publication Year: 2001 , Page(s): 1093 - 1097
    Cited by:  Papers (177)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (160 KB) |  | HTML iconHTML  

    The defining characteristic of a networked control system (NCS) is having a feedback loop that passes through a local area computer network. Our two-step design approach includes using standard control methodologies and choosing the network protocol and bandwidth in order to ensure important closed-loop properties are preserved when a computer network is inserted into the feedback loop. For sufficiently high data rates, global exponential stability is preserved. Simulations are included to demonstrate the theoretical result View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Input-to-state stabilization of switched nonlinear systems

    Publication Year: 2001 , Page(s): 1111 - 1116
    Cited by:  Papers (41)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (224 KB) |  | HTML iconHTML  

    This note derives some sufficient conditions to ensure that the whole switched nonlinear system is input-to-state stabilizable (ISS) when each mode is ISS. Both cases, that the switchings of system modes coincide exactly and that they do not coincide with those of the corresponding controllers, are considered. For the latter, a model-based identification scheme is used to identify the system modes. The proposed scheme can overcome the finite escape time that may happen in this case View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Asymptotic properties of the best sampled-data control performance

    Publication Year: 2001 , Page(s): 1132 - 1137
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (208 KB) |  | HTML iconHTML  

    Properties of the best achievable performance of sampled-data control systems are investigated. Contrary to our intuition, the best sampled-data control performance does not always converge to the best continuous-time control performance, even as the sampling period approaches zero. A counterexample is presented and a lifting-based analysis is performed. It is shown that the performance convergence is guaranteed if, and only if, a certain Hankel norm and an aliasing effect computed from a specified antialiasing filter tend to vanish with a decreasing sampling period. It is also shown that this condition is reduced to a simpler form if the specified filter has special forms. These results can be generalized to a system involving a generalized hold View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An improved closed-loop stability related measure for finite-precision digital controller realizations

    Publication Year: 2001 , Page(s): 1162 - 1166
    Cited by:  Papers (30)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (212 KB) |  | HTML iconHTML  

    The pole-sensitivity approach is employed to investigate the stability issue of the discrete-time control system, where a digital controller implemented with finite word length (FWL), is used. A stability related measure is derived, which is more accurate in estimating the closed-loop stability robustness of an FWL implemented controller than some existing measures for the pole-sensitivity analysis. This improved stability measure thus provides a better criterion to find the optimal realizations for a generic controller structure that includes output-feedback and observer-based controllers. A numerical example is used to verify the theoretical analysis and to illustrate the design procedure View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Advanced cooperative order in a compensator set in passive redundancy

    Publication Year: 2001 , Page(s): 1151 - 1155
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (168 KB) |  | HTML iconHTML  

    Presents the idea of advanced cooperative order in a compensator set with its mathematical model based on passive redundancy. Each compensator has a positive definition of membership in the set that it must contribute to reduction of any other's load in any situation. Such advanced cooperative order can be achieved in a multi-compensator configuration View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Backstepping design with local optimality matching

    Publication Year: 2001 , Page(s): 1014 - 1027
    Cited by:  Papers (28)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (432 KB) |  | HTML iconHTML  

    In nonlinear H-optimal control design for strict-feedback nonlinear systems, our objective is to construct globally stabilizing control laws to match the optimal control law up to any desired order, and to be inverse optimal with respect to some computable cost functional. Our recursive construction of a cost functional and the corresponding solution to the Hamilton-Jacobi-Isaacs equation employs a new concept of nonlinear Cholesky factorization. When the value function for the system has a nonlinear Cholesky factorization, we show that the backstepping design procedure can be tuned to yield the optimal control law View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A continuous feedback approach to global strong stabilization of nonlinear systems

    Publication Year: 2001 , Page(s): 1061 - 1079
    Cited by:  Papers (132)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (500 KB) |  | HTML iconHTML  

    We present a continuous feedback approach to the problem of global strong stabilization, for genuinely nonlinear systems that may not be stabilized, even locally, by any smooth feedback. We describe conditions under which it is possible to prove, while no smooth controllers exist, the existence of continuous state feedback control laws that achieve global strong stability (GSS) in the sense of Kurzweil (1956). The proof is constructive and carried out by developing a machinery, which combines the theory of homogeneous systems with the idea of adding a power integrator, for the explicit construction of globally stabilizing continuous controllers. We then illustrate, by means of examples, how this machinery can be used to overcome the topological obstruction caused by smooth feedback, and hence resulting in new solutions to a variety of open control problems, including global stabilization of an underactuated unstable two degree of freedom mechanical system View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Nonparametric control algorithms for nonlinear fading memory systems

    Publication Year: 2001 , Page(s): 1117 - 1121
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (196 KB) |  | HTML iconHTML  

    We develop an algorithm to control an unknown nonlinear fading memory discrete-time system. Our approach is based on nonparametric regression techniques rather than traditional feedback control. We discuss a procedure that, given a desired periodic output and a tolerance, produces an acceptable output from any system in a wide class. The algorithm uses as data past inputs (which are selected by the algorithm) and corresponding (possibly noisy) output observations and needs no extra parametric knowledge or restrictions on the system. We also present an algorithm that produces an output that converges to the desired output when stricter conditions are imposed on the system. Our approach, in its current form, however, cannot be used to control open-loop unstable systems View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Least squares tracking on the Euclidean group

    Publication Year: 2001 , Page(s): 1127 - 1132
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (192 KB) |  | HTML iconHTML  

    A large class of problems in robotics, e.g., trajectory tracking with obstacle avoidance, compliant motion control, and complex assembly, can be formulated as a least-squares tracking problem on the Euclidean group subject to constraints on the state and/or control. We develop an optimal control framework for this general class of problems, and derive analytic solutions for the local and global versions of the general optimal control problem. Our formalism can be viewed in some sense as an extension to the Euclidean group of the linear quadratic regulator subject to state equality constraints. Examples from force-guided complex assembly and tracking with obstacle avoidance are given View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A modal decomposition of the Hopf normal form coefficient

    Publication Year: 2001 , Page(s): 1080 - 1083
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (124 KB) |  | HTML iconHTML  

    The local stability of a nonlinear dynamical system at an equilibrium point with a pair of purely imaginary eigenvalues can be assessed through the computation of a cubic Hopf normal form coefficient, assuming the remaining eigenvalues have negative real parts. In this paper, a modal decomposition of the Hopf coefficient is proved. The decomposition provides a new methodology for analyzing the Hopf cubic normal form coefficient in a formal way. The framework is illustrated by nonlinear stability analysis of two control designs where it is shown that the Hopf coefficient can be stabilized through modal nonlinear feedbacks View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance lower bounds in stochastic robust and adaptive control

    Publication Year: 2001 , Page(s): 1137 - 1141
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (136 KB) |  | HTML iconHTML  

    The fundamental issues of capability of robust and adaptive control in dealing with uncertainty are investigated in stochastic systems. It is revealed that to capture the intrinsic limitations of adaptive control, it is necessary to use supt types of transient and persistent performance, rather than lim supt types which reflect only asymptotic behavior of a system. For clarity and technical tractability, a simple first-order linear time-varying system is employed as a vehicle to explore performance lower bounds of robust and adaptive control. Optimal performances of nominal, robust and adaptive control are explicitly derived and their implications are discussed in an information framework. An adaptive strategy is scrutinized for its achievable performance bounds. The results indicate that intimate interaction and inherent conflict between identification and control result in a certain performance lower bound which does not approach the nominal performance even when the system varies very slowly. Explicit lower bounds are obtained when disturbances are either normally or uniformly distributed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Preservation of controllability-observability in expanded systems

    Publication Year: 2001 , Page(s): 1155 - 1162
    Cited by:  Papers (16)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (224 KB) |  | HTML iconHTML  

    The result contributed by the article is that controllability-observability of an original continuous-time LTI dynamic system can always be simultaneously preserved in expanded systems within the inclusion principle when using block structured complementary matrices. This new structure offers more degrees of freedom for the selection of specific complementary matrices than well known used cases, such as aggregations and restrictions, which enable such preservation only in certain special cases. A complete unrestricted transmission of these qualitative properties from the original controllable-observable system to its expansion is a basic requirement on the expansion/contraction process, mainly when controllers/observers are designed in expanded systems to be consequently contracted for implementation in initially given systems. An original system composed of two overlapped subsystems is adopted as a general prototype ease. A numerical example is supplied View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On Kalman-Yakubovich-Popov lemma for stabilizable systems

    Publication Year: 2001 , Page(s): 1089 - 1093
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (152 KB) |  | HTML iconHTML  

    The Kalman-Yakubovich-Popov (KYP) lemma has been a cornerstone in system theory and network analysis and synthesis. It relates an analytic property of a square transfer matrix in the frequency domain to a set of algebraic equations involving parameters of a minimal realization in time domain. This note proves that the KYP lemma is also valid for realizations which are stabilizable and observable View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Risk-sensitive decision-theoretic diagnosis

    Publication Year: 2001 , Page(s): 1166 - 1171
    Cited by:  Papers (2)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (172 KB) |  | HTML iconHTML  

    We consider the problem of determining the optimal sequence of tests for the discovery of a faulty component, where there is a random cost associated with testing a component. Our work is motivated by applications in telecommunications networks, e.g., location and isolation of faults (or intruders) in IP networks. A novel feature in our approach is that a risk-sensitive performance criterion is used in order to rank different competing schedules. Risk-sensitivity is incorporated through the use of an exponential utility function, and hence optimal schedules attain a trade-off between minimal expected costs and, e.g., a low variance about the achievable expected costs. We characterize optimal schedules both when the testing sequence is not subject to precedence constraints, and when it is subject to such constraints, given by an arbitrary partial order. For the case with precedence constraints, we show that our models can be analyzed via modular decompositions, as studied by Monma and Sidney (1987) View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the simultaneous stabilization of three or more plants

    Publication Year: 2001 , Page(s): 1101 - 1107
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (200 KB) |  | HTML iconHTML  

    In this note, the problem of the simultaneous stabilization of three multivariable plants is addressed. We consider the general case where the existence of a unit controller cannot be used as a sufficient condition to guarantee the existence of a simultaneous controller for three multivariable plants. The sufficient conditions given in this note lead to a constructive controller design to stabilize simultaneously three multivariable plants. A generalization is proposed for stabilizing simultaneously n multivariable plants View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Asymptotic tracking of periodic trajectories for a simple mechanical system subject to nonsmooth impacts

    Publication Year: 2001 , Page(s): 1122 - 1126
    Cited by:  Papers (31)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (204 KB) |  | HTML iconHTML  

    An infinitely rigid mass is considered, which moves on a plane under the action of proper control forces, within a closed region delimited by an infinitely massive and rigid circular barrier. A suitably amended tracking problem for a class of periodic trajectories, involving an infinite number of nonsmooth impacts between the mass and the barrier, is formally stated and solved View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Structure and stability of certain chemical networks and applications to the kinetic proofreading model of T-cell receptor signal transduction

    Publication Year: 2001 , Page(s): 1028 - 1047
    Cited by:  Papers (54)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (560 KB) |  | HTML iconHTML  

    Deals with the theory of structure, stability, robustness, and stabilization for an appealing class of nonlinear systems which arises in the analysis of chemical networks. The results given here extend, but are also heavily based upon, certain previous work by Feinberg (1977, 1979, 1987, 1995) and Horn and Jackson (1972), of which a self-contained and streamlined exposition is included. The theoretical conclusions are illustrated through an application to the kinetic proofreading model proposed by McKeithan (1995) for T-cell receptor signal transduction View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimal control of a particular class of singularly perturbed nonlinear discrete-time systems

    Publication Year: 2001 , Page(s): 1097 - 1101
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (168 KB) |  | HTML iconHTML  

    This note studies a class of discrete-time nonlinear systems which depend on a small parameter. Using the singular perturbation theory in a systematic way, we give a trajectory approximation result based on the decomposition of the model into reduced and boundary layer models. This decomposition is used to analyze optimal control via maximum principle of such systems. As a result, significant order reduction of optimal control problems is achieved View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Control Lyapunov-Razumikhin functions and robust stabilization of time delay systems

    Publication Year: 2001 , Page(s): 1048 - 1060
    Cited by:  Papers (124)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (404 KB) |  | HTML iconHTML  

    Motivated by control Lyapunov functions and Razumikhin theorems on stability of time delay systems, we introduce the concept of control Lyapunov-Razumikhin functions (CLRF). The main reason for considering CLRFs is construction of robust stabilizing control laws for time delay systems. Most existing universal formulas that apply to CLFs, are not applicable to CLRFs. It turns out that the domination redesign control law applies, achieving global practical stability and, under an additional assumption, global asymptotic stability. This additional assumption is satisfied in the practically important case when the quadratic part of a CLRF is itself a CLRF for the Jacobian linearization of the system. The CLRF based domination redesign possesses robustness to input unmodeled dynamics including an infinite gain margin. While, in general, construction of CLRFs is an open problem, we show that for several classes of time delay systems a CLRF can be constructed in a systematic way View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A framework for state-space estimation with uncertain models

    Publication Year: 2001 , Page(s): 998 - 1013
    Cited by:  Papers (106)  |  Patents (42)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (432 KB)  

    Develops a framework for state-space estimation when the parameters of the underlying linear model are subject to uncertainties. Compared with existing robust filters, the proposed filters perform regularization rather than deregularization. It is shown that, under certain stabilizability and detectability conditions, the steady-state filters are stable and that, for quadratically-stable models, the filters guarantee a bounded error variance. Moreover, the resulting filter structures are similar to various (time- and measurement-update, prediction, and information) forms of the Kalman filter, albeit ones that operate on corrected parameters rather than on the given nominal parameters. Simulation results and comparisons with ℋ guaranteed-cost, and set-valued state estimation filters are provided View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Robust filtering for discrete-time systems with bounded noise and parametric uncertainty

    Publication Year: 2001 , Page(s): 1084 - 1089
    Cited by:  Papers (71)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (236 KB) |  | HTML iconHTML  

    This note presents a new approach to finite-horizon guaranteed state prediction for discrete-time systems affected by bounded noise and unknown-but-bounded parameter uncertainty. Our framework handles possibly nonlinear dependence of the state-space matrices on the uncertain parameters. The main result is that a minimal confidence ellipsoid for the state, consistent with the measured output and the uncertainty description, may be recursively computed in polynomial time, using interior-point methods for convex optimization. With n states, l uncertain parameters appearing linearly in the state-space matrices, with rank-one matrix coefficients, the worst-case complexity grows as O(l(n + l)3.5) With unstructured uncertainty in all system matrices, the worst-case complexity reduces to O(n3.5) View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

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