Showing papers on "Closed-loop pole published in 1995"
01 Jan 1995
TL;DR: In this paper, the authors derived a new rank condition which guarantees the arbitrary pole assignability of a given system by dynamic compensators of degree at most $q$ by using this rank condition, and established several new sufficiency conditions which ensure the arbitrary poles assignability in a generic system.
Abstract: In this paper we derive a new rank condition which guarantees the arbitrary pole assignability of a given system by dynamic compensators of degree at most $q$. By using this rank condition we establish several new sufficiency conditions which ensure the arbitrary pole assignability of a generic system. Our proofs also comes with a concrete numerical procedure to construct a particular compensator which assigns a given set of closed loop poles.
64 citations
01 Jan 1995
TL;DR: The authors establish several new sufficiency conditions which ensure the arbitrary pole assignability of a generic system by dynamic compensators of degree at most q.
Abstract: In this paper we derive a new rank condition which guarantees the arbitrary pole assignability of a given system by dynamic compensators of degree at most $q$. By using this rank condition we establish several new sufficiency conditions which ensure the arbitrary pole assignability of a generic system. Our proofs also comes with a concrete numerical procedure to construct a particular compensator which assigns a given set of closed loop poles.
56 citations
TL;DR: It is shown that when an upper bound of the plant transfer function's H/sup /spl infin//-norm has been supplied, and the noise contaminating the time domain identification experiment data is not too significant, such a transfer function set can be parameterized by a linear fractional transformation of two transfer function matrices.
Abstract: In this paper, we investigate the structure of the transfer function set which includes all the transfer functions deduced from the plant available information. It is shown that when an upper bound of the plant transfer function's H/sup /spl infin//-norm has been supplied, and the noise contaminating the time domain identification experiment data is not too significant, such a transfer function set can be parameterized by a linear fractional transformation of two transfer function matrices. One of them is a fixed transfer function matrix which is completely determined by the plant available information and the noise magnitude. The other is a norm bounded, structure fixed, free transfer function matrix. Moreover, it is shown that the problem of analytically obtaining the fixed complexity nominal model that best approximates this transfer function set is as difficult as the /spl mu/-synthesis problem. >
35 citations
Patent•
06 Jun 1995TL;DR: In this paper, a transfer function of an all-pass filter having the same amplitude as a first pole coefficient of the transfer function and the opposite sign is set, in which the first pole is eliminated, such that an input signal is processed by the new transfer function.
Abstract: In a digital IIR filter having a predetermined transfer function, a transfer function of an all-pass filter having the same amplitude as a first pole coefficient of the transfer function and the opposite sign is set. By synthesizing the transfer function and the transfer function of the set all-pass filter, a new transfer function, in which the first pole is eliminated, is calculated such that an input signal is processed by the new transfer function.
9 citations
TL;DR: The QFT for uncertain MIMO feedback systems is a tool to design the two degree-of-freedom of a feedback system that satisfies demands of robustness, performance, and gain and phase margin at the plant input for diagonal controllers.
8 citations
TL;DR: A fast algorithm is described that computes the impulse response of the vocal tract from its transfer function and is being used in the articulatory speech synthesizer under development both at Rutgers University and at the Royal Institute of Technology, Sweden.
Abstract: This paper describes a fast algorithm that computes the impulse response of the vocal tract from its transfer function. First, numerical methods for computing the transfer function of a given vocal-tract configuration are briefly outlined. These methods include techniques (1) to decompose the numerator and denominator of the transfer function and (2) to efficiently determine the resonance modes of the vocal tract. Next, is a description of how to calculate residues at the poles and how to express the vocal-tract transfer function as a partial fraction expansion series. Each term in the expansion corresponds to an elementary formant generator, and the additive terms correspond to a parallel formant architecture. A second-order digital filter is derived for each formant generator. The impulse response of the vocal tract can therefore be specified compactly by a set of such filters. Good agreement is observed between the directly calculated transfer function and the one synthesized by the proposed algorithm. The algorithm is being used in the articulatory speech synthesizer under development both at Rutgers University and at the Royal Institute of Technology, Sweden. An ambitious goal is to incorporate the method into a text-to-speech synthesizer and/or an adaptive voice mimic system.
8 citations
21 Jun 1995
TL;DR: In this paper, a discrete time adaptive sliding control law for SISO nonlinear systems with mismatched uncertainties is presented, where the control objective is for the output to track a sufficiently smooth desired trajectory.
Abstract: This paper presents a discrete time adaptive sliding control law for SISO nonlinear systems with mismatched uncertainties. The systems are assumed to have no zero dynamics, i.e. the relative degree is the same as the system order. Control objective is for the output to track a sufficiently smooth desired trajectory. The control law utilizes the idea of the multiple sliding surface. The developed discrete time adaptation laws differ from those of conventional sliding control, and aim at adaptation on time varying parameters such as disturbances or unstructured unmodeled dynamics. The close loop stability is checked in the discrete time domain, and exponential decay of the adaptation error can be guaranteed by proper placement of the discrete time closed loop poles.
6 citations
01 Jan 1995
TL;DR: In this paper, the pole assignment controller design under consideration of the control signal saturation is presented, where the closed loop poles can be made quite independently from the saturation effect, i.e. they only have to respect different parasitic effects like quantization and measurement noice, neclected dynamics, etc.
Abstract: This paper deals with the pole assignment controller design under consideration of the control signal saturation. The controller synthesis developed for the double integrator plant is based on the decomposition of the 2nd order dynamics into two particular 1st order movements witch enables, together with the newly introduced geometrical interpretation of closed loop poles, an easy handling of saturation effects and yields a simlpe explicite controller fully respecting the given saturation limits. So, the specification of the closed loop poles can be made quite independently from the saturation effect, i.e. they only have to respect different parasitic effects like quantization and measurement noice, neclected dynamics, etc. It gives to the designer a new “degree of freedom” in comparing with the “linear” pole assignment controllers, where this choice has to take into account also the allowed control signal amplitudes.
5 citations
TL;DR: A method is developed to efficiently compute the closed loop transfer function and intermediate transfer functions of a linear system.
Abstract: The problem of computing the closed loop transfer function of a linear system represented by its block diagram or by its flow graph is of importance in CAD programs designed for the analysis of linear systems. Mason's rule (1953) is one of the available techniques to perform such calculations, but it requires searching into the graph for different paths and loops and becomes slow as system complexity increases. In this paper, a method is developed to efficiently compute the closed loop transfer function and intermediate transfer functions of a linear system. >
4 citations
TL;DR: A unified theory of identification in a feedback system is presented from the viewpoint of inverse problem on reactor noise and notes on system identification are discussed on an open loop transfer function in a low power reactor and on effects of diagonalization in covariance space of noise sources.
Abstract: A unified theory of identification in a feedback system is presented from the viewpoint of inverse problem on reactor noise. A power reactor described by a 4 block feedback model is expressed in terms of equivalent correlation functions as a 5 block feedback model with an additional loop, if one of subsystems of the reactor becomes unstable, however, the total system is stable by negative feedback effects, and if noise sources are not independent. The addition of a loop in the feedback system leads errors in estimation of open loop transfer functions. In the case, modified open loop transfer functions are identified instead of original ones. From the viewpoint of reactor diagnosis, notes on system identification are discussed on an open loop transfer function in a low power reactor and on effects of diagonalization in covariance space of noise sources.
3 citations
13 Dec 1995
TL;DR: In this article, the impact of the directions associated with unstable poles and on the issue of internal stability in closed loop systems was studied, and the authors concluded that the effect of unstable poles on the internal stability of a closed loop system is negligible.
Abstract: This paper studies the impact of the directions associated with unstable poles and on the issue of internal stability in closed loop systems.
13 Dec 1995
TL;DR: It is established that the Grassmann invariant form of linear multivariable system (rigorously, multivector nonzero decomposable form over a rational vector space associated with transfer function matrix), presents a global, minimal and complete feedback invariants in linear output feedback pole-assignment condition.
Abstract: It will be shown that a complete set of feedback invariants for linear (or static) output feedback is explicitly defined under the Grassman space framework. Specifically, it is established that the Grassmann invariant form of linear multivariable system (rigorously, multivector nonzero decomposable form over a rational vector space associated with transfer function matrix), presents a global, minimal and complete feedback invariant form in linear output feedback pole-assignment condition. A former negative preclusion, nonclosed orbit problem for output feedback equivalence in linear algebraic group approach, is re-analyzed in the Grassmann invariant condition (so called, Plucker matrix full-rank condition). A constructive algorithm for the complete feedback invariant form is given and illustrated in a concrete way.
13 Dec 1995
TL;DR: In this paper, minimal realisations of square, nonsingular and strictly proper transfer matrices are considered and equivalance classes of all such realizations under the transformation group generated by similarity transformations and constant output feedback are characterized via a canonical form.
Abstract: In this paper, we consider minimal realisations of square, nonsingular and strictly proper transfer matrices. Equivalance classes of all such realizations under the transformation group generated by similarity transformations and constant output feedback are characterized via a canonical form. The canonical form is also used to derive a necessary condition for arbitrary pole placement by constant output feedback and another necessary condition for stabilization by constant output feedback.
13 Dec 1995
TL;DR: In this paper, a rank condition that guarantees the arbitrary pole assignability of a given system by dynamic compensators of degree at most q is given, where q is the number of closed loop poles in the system.
Abstract: In this paper we give a rank condition which guarantees the arbitrary pole assignability of a given system by dynamic compensators of degree at most q. By using this rank condition we establish a new strong sufficiency condition which ensures the arbitrary pole assignability of the generic system. Our proof also comes with a concrete numerical procedure to construct a particular compensator which assigns a given set of closed loop poles.
12 Mar 1995
TL;DR: In this article, it is shown that manipulations within the Youla parameterization of all stabilizing controllers yield controllers with order equal to the system observability index /spl upsi/sub 0/ that can generate any desired linear combination of the system state variables.
Abstract: Efforts in designing controllers of order less than n-m-l+1 for systems modeled by n state, m input, l output minimal state space realizations are presented. It is shown that manipulations within the Youla parameterization of all stabilizing controllers yield controllers with order equal to the system observability index /spl upsi//sub 0/ that can generate any desired linear combination of the system state variables. It is possible to place the closed loop poles for a minimal realization with such a linear combination, so the method may be used for controller design. Because /spl upsi//sub 0/, is often less than the plant order for large multiinput-multioutput (MIMO) plant realizations, the method may prove to be a viable reduced order controller design tool. The technique is used on a tenth order model of an existing NASA test facility to generate a fifth order stabilizing controller. >
01 Jan 1995
TL;DR: In this article, the problem of finding the best closed loop poles for a system whose order is restricted to less than that for the Z1 optimal solution is addressed. But the problem is not addressed in this paper.
Abstract: In the work presented here, we address the issue of fiiding the best closed loop poles for a system whose order is restricted to be less than that for the Z1 optimal solution. We incorporate specification of one closed loop pole into the minimisation problem formulation. We obtain the dual problem and use it to obtain closed form solutions to a simple problem.
13 Dec 1995
TL;DR: In this paper, the authors incorporate placement of one real closed loop pole into an l/sub 1/ controller design problem, that of designing a stabilising feedback compensator to minimise the tracking error when following a specified bounded command in a SISO discrete-time system.
Abstract: In this paper we incorporate placement of one real closed loop pole into an l/sub 1/ controller design problem-that of designing a stabilising feedback compensator to minimise the l/sub 1/ norm of the tracking error when following a specified bounded command in a SISO discrete-time system. It is well known that the optimal solution to this problem involves a deadbeat closed loop map of finite, but possibly very high order, from command to tracking error. We show that for a class of plants, if the controller order is to be less than that required for the l/sub 1/-optimal solution, it is better to use closed loop pole locations other than deadbeat.
13 Dec 1995
Abstract: For a general H/sub 2/ optimal control problem, at first all H/sub 2/ optimal measurement feedback controllers are characterized and parameterized, and then attention is focused on controllers with observer based architecture. An important problem that can be coined as an H/sub 2/ optimal control problem with simultaneous pole placement, is formulated and solved. That is, since in general there exist many H/sub 2/ optimal measurement feedback controllers, utilizing such flexibility and freedom, we can solve the problem of simultaneously placing the closed-loop poles at desirable locations whenever possible while still preserving H/sub 2/ optimality. We discuss here only full order observer based controllers. The discussion of reduced order observer based controllers follows along the same lines.