By Topic

Automatic Control, IEEE Transactions on

Issue 11 • Date Nov. 2011

Filter Results

Displaying Results 1 - 25 of 33
  • Table of contents

    Publication Year: 2011 , Page(s): C1 - C4
    Save to Project icon | Request Permissions | PDF file iconPDF (38 KB)  
    Freely Available from IEEE
  • IEEE Control Systems Society

    Publication Year: 2011 , Page(s): C2
    Save to Project icon | Request Permissions | PDF file iconPDF (38 KB)  
    Freely Available from IEEE
  • Scanning the issue

    Publication Year: 2011 , Page(s): 2497 - 2498
    Save to Project icon | Request Permissions | PDF file iconPDF (36 KB)  
    Freely Available from IEEE
  • The Behavioral Approach to Linear Parameter-Varying Systems

    Publication Year: 2011 , Page(s): 2499 - 2514
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (727 KB) |  | HTML iconHTML  

    Linear parameter-varying (LPV) systems are usually described in either state-space or input-output form. When analyzing system equivalence between different representations it appears that the time-shifted versions of the scheduling signal (dynamic dependence) need to be taken into account. Therefore, representations used previously to define and specify LPV systems are not equal in terms of dynamics. In order to construct a parametrization-free description of LPV systems that overcomes these difficulties, a behavioral approach is introduced that serves as a basis for specifying system theoretic properties. LPV systems are defined as the collection of trajectories of system variables (like inputs and outputs) and scheduling variables. LPV kernel, input-output, and state-space system representations are introduced with appropriate equivalence transformations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Monte Carlo Optimization and Dynamic Programming Approach for Managing MRI Examinations of Stroke Patients

    Publication Year: 2011 , Page(s): 2515 - 2529
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (716 KB) |  | HTML iconHTML  

    Quick diagnosis is critical to stroke patients, but it relies on expensive and heavily used imaging equipment. This results in long waiting times with potential threats to the patient's life. It is important for neurovascular departments treating stroke patients to reduce waiting times for diagnosis. This paper proposes a reservation process of magnetic resonance imaging (MRI) examinations for stroke patients. The neurovascular department reserves a certain number of appropriately distributed contracted time slots (CTS) to ensure quick diagnosis of stroke patients. Additional MRI time slots can also be reserved by regular reservations (RTS). The problem consists in determining the contract and the control policy to assign patients to either CTS or RTS in order to reach the best compromise between the waiting times and unused CTS. Structural properties of the optimal control policy are proved by an average-cost Markov decision process (MDP) approach. The contract is determined by combining a Monte Carlo approximation approach and local search. Extensive numerical experiments are performed to show the efficiency of the proposed approach and to investigate the impact of different parameters. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Multiresolution Approximation Method for Fast Explicit Model Predictive Control

    Publication Year: 2011 , Page(s): 2530 - 2541
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1183 KB) |  | HTML iconHTML  

    A model predictive control law is given by the solution to a parametric optimization problem that can be pre-computed offline and provides an explicit map from state to control input. In this paper, an algorithm is introduced based on wavelet multiresolution analysis that returns a low complexity explicit model predictive control law built on a hierarchy of second-order interpolets. The resulting interpolation is shown to be everywhere feasible and continuous. Further, tests to confirm stability and to compute a bound on the performance loss are introduced. Since the controller approximation is built on a grid hierarchy, convergence to a stabilizing control law is guaranteed and the evaluation of the control law in real-time systems is naturally fast and runs in a bounded logarithmic time. Two examples are provided; A two-dimensional example with an evaluation speed of 31 ns and a four-dimensional example with an evaluation speed of 119 ns. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Dead-Time Compensation for Systems With Multiple I/O Delays: A Loop-Shifting Approach

    Publication Year: 2011 , Page(s): 2542 - 2554
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (597 KB) |  | HTML iconHTML  

    This paper studies the standard problem for a class of multiple-delay systems, where different input/output channels have different dead times. We present a procedure of converting the original problem to an equivalent delay-free problem via loop-shifting arguments. This brings about and, for the first time, explains an unorthodox form of the dead-time compensator, called the feedforward action Smith predictor (FASP), in which an interchannel feedforward term is present alongside the conventional internal feedback. Our developments lead to a qualitative conclusion that the structure of the dead-time compensator should rely upon the structure of the regulated output and/or the way in which exogenous signals affect the measurement. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Quaternion-Based Hybrid Control for Robust Global Attitude Tracking

    Publication Year: 2011 , Page(s): 2555 - 2566
    Cited by:  Papers (27)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (590 KB) |  | HTML iconHTML  

    It is well known that controlling the attitude of a rigid body is subject to topological constraints. We illustrate, with examples, the problems that arise when using continuous and (memoryless) discontinuous quaternion-based state-feedback control laws for global attitude stabilization. We propose a quaternion-based hybrid feedback scheme that solves the global attitude tracking problem in three scenarios: full state measurements, only measurements of attitude, and measurements of attitude with angular velocity measurements corrupted by a constant bias. In each case, the hybrid feedback is dynamic and incorporates hysteresis-based switching using a single binary logic variable for each quaternion error state. When only attitude measurements are available or the angular rate is corrupted by a constant bias, the proposed controller is observer-based and incorporates an additional quaternion filter and bias observer. The hysteresis mechanism enables the proposed scheme to simultaneously avoid the “unwinding phenomenon” and sensitivity to arbitrarily small measurement noise that is present in discontinuous feedbacks. These properties are shown using a general framework for hybrid systems, and the results are demonstrated by simulation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Stability and Performance of SISO Control Systems With First-Order Reset Elements

    Publication Year: 2011 , Page(s): 2567 - 2582
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (903 KB) |  | HTML iconHTML  

    We consider set-point regulation and L2 robust stability properties of a class of reset control systems consisting of a minimum-phase relative degree-one linear SISO plant controlled by a novel first-order reset element (FORE). These results rely on necessary and sufficient conditions for exponential and L2 finite gain stability of a class of planar reset systems consisting of a scalar linear plant controlled by the novel FORE. We show that the L2 gain of the planar reset system decreases to zero as the pole and/or the gain of the FORE are increased to infinity. A number of stability results, including Lyapunov conditions for Lp and exponential stability, for a larger class of reset and hybrid systems are presented and used to prove our main results. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Computing Abstractions of Nonlinear Systems

    Publication Year: 2011 , Page(s): 2583 - 2598
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (768 KB) |  | HTML iconHTML  

    Sufficiently accurate finite state models, also called symbolic models or discrete abstractions, allow one to apply fully automated methods, originally developed for purely discrete systems, to formally reason about continuous and hybrid systems and to design finite state controllers that provably enforce predefined specifications. We present a novel algorithm to compute such finite state models for nonlinear discrete-time and sampled systems which depends on quantizing the state space using polyhedral cells, embedding these cells into suitable supersets whose attainable sets are convex, and over-approximating attainable sets by intersections of supporting half-spaces. We prove a novel recursive description of these half-spaces and propose an iterative procedure to compute them efficiently. We also provide new sufficient conditions for the convexity of attainable sets which imply the existence of the aforementioned embeddings of quantizer cells. Our method yields highly accurate abstractions and applies to nonlinear systems under mild assumptions, which reduce to sufficient smoothness in the case of sampled systems. Its practicability in the design of discrete controllers for nonlinear continuous plants under state and control constraints is demonstrated by an example. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Combination of Lyapunov and Density Functions for Stability of Rotational Motion

    Publication Year: 2011 , Page(s): 2599 - 2607
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (843 KB) |  | HTML iconHTML  

    Lyapunov methods and density functions provide dual characterizations of the solutions of a nonlinear dynamic system. This work exploits the idea of combining both techniques, to yield stability results that are valid for almost all the solutions of the system. Based on the combination of Lyapunov and density functions, analysis methods are proposed for the derivation of almost input-to-state stability, and of almost global stability in nonlinear systems. The techniques are illustrated for an inertial attitude observer, where angular velocity readings are corrupted by non-idealities. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multi-Decision Supervisory Control: Parallel Decentralized Architectures Cooperating for Controlling Discrete Event Systems

    Publication Year: 2011 , Page(s): 2608 - 2622
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (521 KB) |  | HTML iconHTML  

    This paper deals with decentralized supervisory control, where a set of local supervisors cooperate in order to achieve a given global specification by controlling a discrete event system. We propose a new framework, called multi-decision control, whose basic principle consists in using several decentralized supervisory control architectures working in parallel and whose decisions are combined disjunctively or conjunctively. We have identified sufficient conditions that make a decentralized architecture eligible to be used in the multi-decision framework. We have studied the generic framework consisting of several eligible architectures running in parallel, and we have also considered in detail the particular case of several inference-based InfNj-supervisors running in parallel. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • How Good is Quantized Model Predictive Control With Horizon One?

    Publication Year: 2011 , Page(s): 2623 - 2638
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (667 KB) |  | HTML iconHTML  

    Model Predictive Control is increasingly being used in areas where decision variables are constrained to finite or countably infinite sets. Well known fields include Power Electronics, Signal Processing, and Telecommunications. Typically, the applications utilize high speed sampling and, thus, there is an incentive to reduce computational burden. One way of achieving this is to use small optimization horizons. This raises the question as to the optimality and performance of control laws with short horizons. In this paper, we give necessary and sufficient conditions for horizon one quantized model predictive control to be equivalent to the use of larger horizons. We also explore situations where horizon one is near optimal. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • State Observability and Observers of Linear-Time-Invariant Systems Under Irregular Sampling and Sensor Limitations

    Publication Year: 2011 , Page(s): 2639 - 2654
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (584 KB) |  | HTML iconHTML  

    State observability and observer designs are investigated for linear-time-invariant systems in continuous time when the outputs are measured only at a set of irregular sampling time sequences. The problem is primarily motivated by systems with limited sensor information in which sensor switching generates irregular sampling sequences. State observability may be lost and the traditional observers may fail in general, even if the system has a full-rank observability matrix. It demonstrates that if the original system is observable, the irregularly sampled system will be observable if the sampling density is higher than some critical frequency, independent of the actual time sequences. This result extends Shannon's sampling theorem for signal reconstruction under periodic sampling to system observability under arbitrary sampling sequences. State observers and recursive algorithms are developed whose convergence properties are derived under potentially dependent measurement noises. Persistent excitation conditions are validated by designing sampling time sequences. By generating suitable switching time sequences, the designed state observers are shown to be convergent in mean square, with probability one, and with exponential convergence rates. Schemes for generating desired sampling sequences are summarized. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Filtering for Discrete-Time Networked Nonlinear Systems With Mixed Random Delays and Packet Dropouts

    Publication Year: 2011 , Page(s): 2655 - 2660
    Cited by:  Papers (26)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (327 KB) |  | HTML iconHTML  

    In this technical note, a new class of discrete-time networked nonlinear systems with mixed random delays and packet dropouts is introduced, and the H filtering problem for such systems is investigated. The mixed stochasitc time-delays consist of both discrete and infinite distributed delays and the packet dropout phenomenon occurs in a random way. Furthermore, new techniques are presented to deal with the infinite distributed delay in the discrete-time domain. Sufficient conditions for the existence of an admissible filter are established, which ensure the asymptotical stability as well as a prescribed H performance. Finally, examples are given to demonstrate the effectiveness of the proposed filter design scheme in this technical note. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Motion Recovery by Using Stereo Perspective Observation

    Publication Year: 2011 , Page(s): 2660 - 2665
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (262 KB) |  | HTML iconHTML  

    The motion recovery for a class of movements in the space is considered in this note by using the stereo perspective observation of at least three points. The motion equation that is considered can cover a wide class of practical movements in the space. The asymptotic estimation of the motion parameters, which are all time-dependent variables, is developed based on the second method of Lyapunov. Furthermore, the proposed algorithm can be modified to deal with occlusion phenomenon. To illustrate the performance of the proposed algorithm, it is compared with the extended Kalman filter (EKF) by computer simulations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Lur'e Lyapunov Function and Absolute Stability Criterion for Lur'e Singularly Perturbed Systems

    Publication Year: 2011 , Page(s): 2666 - 2671
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (214 KB) |  | HTML iconHTML  

    This technical note investigates the absolute stability problem for Lur'e singularly perturbed systems with multiple nonlinearities. The objective is to determine if the system is absolutely stable for any ε ∈ (0,ε0), where ε denotes the perturbation parameter and ε0 is a pre-defined positive scalar. First, an ε-dependent Lur'e Lyapunov function is constructed that facilitates the stability analysis of the singularly perturbed system. Then, a stability criterion expressed in terms of ε-independent linear matrix inequalities (LMIs) is derived. Based on the stability criterion, an algorithm is proposed to compute the stability bound that is shown to be less conservative than those computed using other existing methods. Finally, examples are given to show the feasibility and effectiveness of the obtained method. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Minimal Time Control of Fed-Batch Processes With Growth Functions Having Several Maxima

    Publication Year: 2011 , Page(s): 2671 - 2676
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (395 KB) |  | HTML iconHTML  

    We address the issue of minimal time optimal control of fed-batch reactor in presence of complex non monotonic kinetics. Several extremal paths with singular arcs can be locally optimal. We show how a regularization technique can help determining the optimal synthesis, based on a numerical approach. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Hierarchical Least Squares Identification for Linear SISO Systems With Dual-Rate Sampled-Data

    Publication Year: 2011 , Page(s): 2677 - 2683
    Cited by:  Papers (22)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (338 KB) |  | HTML iconHTML  

    This technical note studies identification problems for dual-rate sampled-data linear systems with noises. A hierarchical least squares (HLS) identification algorithm is presented to estimate the parameters of the dual-rate ARMAX models. The basic idea is to decompose the identification model of a dual-rate system into several sub-identification models with smaller dimensions and fewer parameters. The proposed algorithm is more computationally efficient than the recursive least squares (RLS) algorithm since the RLS algorithm requires computing the covariance matrix of large sizes, while the HLS algorithm deals with the covariance matrix of small sizes. Compared with our previous work, a detailed study of the HLS algorithm is conducted in this technical note. The performance analysis and simulation results confirm that the estimation accuracy of the proposed algorithm are close to that of the RLS algorithm, but the proposed algorithm retains much less computational burden. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Stability-Preserving Optimization in the Presence of Fast Disturbances

    Publication Year: 2011 , Page(s): 2683 - 2687
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (308 KB) |  | HTML iconHTML  

    We present algebraic conditions on the trajectory of a dynamical system to approximately describe a certain type of system robustness. The corresponding equations can be used as constraints in a robust optimization procedure to select a set of optimal design parameters for a dynamical system which is subject to fast disturbances. Robustness is ensured by requiring the disturbance parameters to stay sufficiently far away from critical manifolds in the disturbance parameter space, at which the system would lose stability. The closest distance to the critical manifolds is measured along their normal vectors. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Approximate Abstractions of Stochastic Hybrid Systems

    Publication Year: 2011 , Page(s): 2688 - 2694
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (310 KB) |  | HTML iconHTML  

    We present a constructive procedure for obtaining a finite approximate abstraction of a discrete-time stochastic hybrid system. The procedure consists of a partition of the state space of the system and depends on a controllable parameter. Given proper continuity assumptions on the model, the approximation errors introduced by the abstraction procedure are explicitly computed and it is shown that they can be tuned through the parameter of the partition. The abstraction is interpreted as a Markov set-Chain. We show that the enforcement of certain ergodic properties on the stochastic hybrid model implies the existence of a finite abstraction with finite error in time over the concrete model, and allows introducing a finite-time algorithm that computes the abstraction. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Lower Bound for Distributed Averaging Algorithms on the Line Graph

    Publication Year: 2011 , Page(s): 2694 - 2698
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (209 KB) |  | HTML iconHTML  

    We derive lower bounds on the convergence speed of a widely used class of distributed averaging algorithms. In particular, we prove that any distributed averaging algorithm whose state consists of a single real number and whose (possibly nonlinear) update function satisfies a natural smoothness condition has a worst case running time of at least on the order of n2 on a line network of n nodes. Our results suggest that increased memory or expansion of the state space is crucial for improving the running times of distributed averaging algorithms. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Integral Sliding Mode Control for Nonlinear Systems With Matched and Unmatched Perturbations

    Publication Year: 2011 , Page(s): 2699 - 2704
    Cited by:  Papers (17)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (224 KB) |  | HTML iconHTML  

    We consider the problem of designing an integral sliding mode controller to reduce the disturbance terms that act on nonlinear systems with state-dependent drift and input matrix. The general case of both, matched and unmatched disturbances affecting the system is addressed. It is proved that the definition of a suitable sliding manifold and the generation of sliding modes upon it guarantees the minimization of the effect of the disturbance terms, which takes place when the matched disturbances are completely rejected and the unmatched ones are not amplified. A simulation of the proposed technique, applied to a dynamically feedback linearized unicycle, illustrates its effectiveness, even in presence of nonholonomic constraints. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Stochastic Receding Horizon Control With Bounded Control Inputs: A Vector Space Approach

    Publication Year: 2011 , Page(s): 2704 - 2710
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (632 KB) |  | HTML iconHTML  

    We design receding horizon control strategies for stochastic discrete-time linear systems with additive (possibly) unbounded disturbances while satisfying hard bounds on the control actions. We pose the problem of selecting an appropriate optimal controller on vector spaces of functions and show that the resulting optimization problem has a tractable convex solution. Under marginal stability of the zero-control and zero-noise system we synthesize receding horizon polices that ensure bounded variance of the states while enforcing hard bounds on the controls. We provide examples that illustrate the effectiveness of our control strategies, and how quantities needed in the formulation of the resulting optimization problems can be calculated off-line. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Finite-Time Attitude Tracking Control of Spacecraft With Application to Attitude Synchronization

    Publication Year: 2011 , Page(s): 2711 - 2717
    Cited by:  Papers (30)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (290 KB) |  | HTML iconHTML  

    This note investigates the finite-time attitude control problems for a single spacecraft and multiple spacecraft. First of all, a finite-time controller is designed to solve finite-time attitude tracking problem for a single spacecraft. Rigorous proof shows that the desired attitude can be tracked in finite time in the absence of disturbances. In the presence of disturbances, the tracking errors can reach a region around the origin in finite time. Then, based on the neighbor rule, a distributed finite-time attitude control law is proposed for a group of spacecraft with a leader-follower architecture. Under the finite-time control law, the attitude synchronization can be achieved in finite time. 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