This paper combines the discrete periodic controller with adaptive pole assignment control system to present a model reference adaptive control system An adaptive periodic gain is developed which assigns the system ze...
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This paper combines the discrete periodic controller with adaptive pole assignment control system to present a model reference adaptive control system An adaptive periodic gain is developed which assigns the system zeros to achieve adaptive model matching. This scheme overcomes the difficulty of unstable pole- zero cancellations in standard model reference adaptive control systems. and thus can be applied to a non-minimum phase plant.
A local observability matrix for a linear time-varying system is introduced. The matrix is useful for observability analysis; it is much easier to use than the usual observability grammian for linear time-varying syst...
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A local observability matrix for a linear time-varying system is introduced. The matrix is useful for observability analysis; it is much easier to use than the usual observability grammian for linear time-varying systems. The matrix is applied to a terrain-aided inertial navigation system to reveal the observability of the system in terms of the nature of the terrain. Results of a simulated covariance analysis are presented and discussed.< >
This paper presents an iterative adaptive pole assignment control algorithm which iteratively solves the Diophantine equation to reduce the on line Computation load of the adaptive control law. A set of conditions are...
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This paper presents an iterative adaptive pole assignment control algorithm which iteratively solves the Diophantine equation to reduce the on line Computation load of the adaptive control law. A set of conditions are provided under which the closed loop system is stable. The system properties are illustrated by a simulation example.
For the basic LTV (Linear Time Varying) disturbance attenuation problem with perfect or delayed state measurements, we obtain a complete characterization of the l 2 -bounded worst-case disturbance, which turns out to ...
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For the basic LTV (Linear Time Varying) disturbance attenuation problem with perfect or delayed state measurements, we obtain a complete characterization of the l 2 -bounded worst-case disturbance, which turns out to be a correlated random vector sequence with a discrete distribution.
Based on the integral manifold concept, a controller is designed that achieves asymptotic tracking and disturbance rejection in a class of nonlinear systems. If the given nonlinear MIMO plant is exponentially stable a...
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Based on the integral manifold concept, a controller is designed that achieves asymptotic tracking and disturbance rejection in a class of nonlinear systems. If the given nonlinear MIMO plant is exponentially stable and has a nonvanishing I/O gain, we show that the control governed by a low gain nonlinear compensator solves this robust servomechanism problem. We also show how the range of initial conditions determines the servo rate of a successful tracking process.
作者：
T. BaşarDecision and Control Laboratory
Coordinated Science Laboratory and the Department of Electrical and Computer Engineering University of Illinois 1101 W. Springfield Avenue Urbana IL 61801 USA
A currently popular controller design technique for linear time-invariant (LTI) systems is H ∞ -optimization, which involves the minimization of the H ∞ -norm of a certain transfer function matrix. When formulated i...
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A currently popular controller design technique for linear time-invariant (LTI) systems is H ∞ -optimization, which involves the minimization of the H ∞ -norm of a certain transfer function matrix. When formulated in the time domain, using state space description, this optimum design problem can be shown to be equivalent to a linear-quadratic differential game, and this formulation provides a convenient set-up for also studying finite-horizon versions of the original infinite-horizon problem. In this differential game, the minimizer is the controller and the maximizer is the unknown disturbance which is subject to an L 2 energy constraint. The performance of interest is the upper value of the differential game, with the controller achieving that value called the minimax controller. In this paper, we formulate such a differential game problem which arises in the context of disturbance rejection, but in the discrete time and under l 1 -bounded disturbances. We study the derivation of the minimax controller associated with the game, as well as the characterization of the worst-case disturbance. We show, in the context of a two-stage design problem, that the saddle point of the game involves a random disturbance, unless the initial state exceeds a certain threshold. Another feature of the solution is that the minimax controller is generally not unique, with the linear feedback controller being outperformed by nonlinear and/or memory controllers, locally or regionally.
作者：
T. BaşarR. SrikantDecision and Control Laboratory
Coordinated Science and Laboratory and the Department of Electrical and Computer Engineering University of Illinois 1101 W. Springfied Avenue Urbana IL 61801 USA
The main objective of this Papers is to develop a new iterative approach towards the Solution of dynamic stochastic teams when the coupling among a subset of agents is weak. either throughth the state dynamics or thro...
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The main objective of this Papers is to develop a new iterative approach towards the Solution of dynamic stochastic teams when the coupling among a subset of agents is weak. either throughth the state dynamics or through the performance index. In each case. the weak coupling is characterized in terms of number of small (pertuhrltion) parameters. When these parameter values are set equal to Zero . the original fairly complex dynamic team. with a quasiclassical or a non classica information pattern is decomposed into relatively simpler storhastic control and team *** solution of which make up t he zerorh order approximation (in a function space) to the team-optimal solution of the original problem. Using this asastarling point for an ite ra tion. We show that approximations of all orders can be obtained by solving a sequence of stochastic control and/or simplper team problems. The paper studies. particlliarly two agents LQG *** quasiciassicai or non classical information patterns. but the approach is applicable to other models (with more than two agents and non-Gaussian sta tislics) as well.
It has recently been shown that a first order compensator robustly stabilizes an interval plant family if and only if it stabilizes all of the extreme plants. That is, if the plant is described by m-th order numerator...
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It has recently been shown that a first order compensator robustly stabilizes an interval plant family if and only if it stabilizes all of the extreme plants. That is, if the plant is described by m-th order numerator and monic n-th order denominator with coefficients lying in prescribed intervals, it is necessary and sufficient to stabilize the set of 2 m+n+l extreme plants. These extreme plants are obtained by considering all possible combinations for the extreme values of the numerator and denominator coefficients. In this paper, we prove a stronger result. Namely, it is necessary and sufficient to stabilize only sixteen of the extreme plants. These sixteen plants are generated using the Kharitonov polynomials associated with the numerator and denominator. Furthermore, when additional apriori information about the compensator is specified (sign of the gain and signs and relative magnitudes of the pole and zero), then in some cases, it is necessary and sufficient to stabilize eight critical plants while in other cases, it is necessary and sufficient to stabilize twelve critical plants.
In this paper we consider a mixed H 2 /H ∞ -optimal control problem. It is assumed that the plant as well as the feedback controller are finite-dimensional and linear time-invariant, and that the plants state is avai...
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In this paper we consider a mixed H 2 /H ∞ -optimal control problem. It is assumed that the plant as well as the feedback controller are finite-dimensional and linear time-invariant, and that the plants state is available for feedback. More specifically, among all the state-feedback controllers that minimize the H 2 -norm of a closed loop transfer matrix, we give necessary and sufficient conditions for the existence of a controller that also satisfies a prescribed H ∞ -norm bound on some other closed loop transfer matrix. When these conditions are satisfied, the solution to the above problem is also a global solution to the constrained optimization problem of minimizing an H 2 -norm performance measure subject to an H ∞ -norm constraint. We also give state-space formulae for computing the solutions. An example is given in which all solutions to the constrained optimization problem are necessarily dynamic, i.e, there is no static gain solution even though plant state is available for feedback. A conclusion of this work is that a priori assumptions on the structure of the solutions to mixed H 2 /H ∞ problems could turn out to be conserative.
The demand for wider, thinner rolled steel has led to an increasing interest in the control of the strip “shape”. Mechanisms for controlling shape include roll bending, roll tilt (or mill steer) and spray pattern co...
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The demand for wider, thinner rolled steel has led to an increasing interest in the control of the strip “shape”. Mechanisms for controlling shape include roll bending, roll tilt (or mill steer) and spray pattern control. This paper will principally focus on an analysis of the spray control system and the associated interaction between adjacent zones. This paper decribes a new approach to shape control, a mathematical model is derived for the dynamic thermal expansion of the rolls of the a tandem cold rolling mill. The model structure has been specifically designed to facilitate control studies. The system is highly non-linear but the model suggests how the system can be linearized by an appropriate input signal transformation. The linearized system then represents a coupled multi-input multi-output dynamical system linking the cooling water sprays to the measured exit strip shape. This linearized model leads to a dynamical decoupling procedure which reduces the system to a set of single-input single—output control systems. Apart from the application to shape control, the method proposed here has more general applicability since the same kind of problem arises in a variety of cross-machine probelms.
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