A New, Necessary and Sufficient Vertex Solution for Robust Stability Check of Unstructured Convex Combination Matrix Families

2015 ◽  
Author(s):  
Rama K. Yedavalli
Keyword(s):  
Robust Stability ◽  
Convex Combination ◽  
Convexity Property ◽  
Ecological Principles ◽  
Sign Structure ◽  
Previous Solution ◽  
Peer Community ◽  
The Stability ◽  
Necessary And Sufficient ◽  
Complete Dependence

This paper revisits the problem of checking the robust stability of matrix families generated by ‘Unstructured Convex Combinations’ of user supplied or externally supplied Vertex Matrices. A previous solution given by the author for this problem involved complete dependence on the quantitative (eigenvalue information) of a set of special matrices labeled the Kronecker Nonsingularity (KN) matrices. In this solution, the ‘convexity’ property is not explicit and transparent, to the extent that, unfortunately, the accuracy of the solution itself is being questioned and not embraced by the peer community. To erase this unforunate and unwarranted image of this author (in this specific problem) in the minds of the peer community, in this paper, the author treads a new path to find a solution that brings out the convexity property in an explicit and understandable way. In the new solution presented in this paper, we combine the qualitative (sign) as well as quantitative (magnitude) information of these KN matrices and present a vertex solution in which the convexity property of the solution is transparent making it more elegant and accepatble to the peer community, than the previous solution. The new solution clearly underscores the importance of using the sign structure of a matrix in assessing the stability of a matrix. This new solution is made possible by the new insight provided by the qualitative (sign) stability/instability derived from ecological principles. Examples are given which clearly demonstrate effectiveness of the new, convexity based algorithm. It is hoped that this new solution will be embraced by the peer community.

Robust Stability Analysis of “Unstructured” Convex Combinations of Matrices With Applications

2006 ◽  
Author(s):  
Rama K. Yedavalli
Keyword(s):  
Stability Analysis ◽  
Robust Stability ◽  
Convex Combination ◽  
Problem Formulation ◽  
Solution Algorithms ◽  
Robust Stability Analysis ◽  
Problem Formulations ◽  
The Stability ◽  
Careful Distinction ◽  
Stable Vertex

This paper presents new insight into the robust stability analysis of families of matrices described by convex combinations of Hurwitz stable 'vertex' matrices. Significant new insight is provided that removes many misconceptions that currently prevail in this problem formulation. In this connection, careful distinction is made between 'Structured' and 'Unstructured' convex combinations of matrices. The convex combinations arising from an uncertain matrix with interval parameters is labeled as 'structured' convex combinations whereas the convex combinations of 'user specified' Hurwitz stable vertex matrices are labeled as 'unstructured' convex combinations. It is clearly shown that the convex combination property in matrix case is dictated more by the nature of the 'vertex' matrices rather than by simply assigning values to the coefficients of the combination. From this analysis, it is clearly established that 'structured' and 'unstructured' convex combinations are two entirely different problem formulations and one is not a special case of the other as it is currently believed. Thus even the solution algorithms for checking the stability of these matrix families are different. After establishing this distinction, this paper then concentrates on the 'unstructured' case and provides a 'vertex solution' to a specific three vertex convex combination problem. The algorithm is illustrated with several examples. This contribution suggests that there is still considerable research needed to appreciably enhance the knowledge base in the important area of robust stability analysis of matrix families which arise in various applications.

A New Algorithm for Testing the Stability of a Polytope: A Geometric Approach for Simplification

1996 ◽  
Vol 118 (3) ◽  
pp. 611-615 ◽  
Author(s):  
Jinsiang Shaw ◽  
Suhada Jayasuriya
Keyword(s):  
Characteristic Equation ◽  
Robust Stability ◽  
Geometric Structure ◽  
Geometric Approach ◽  
Geometric Interpretation ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
The Stability ◽  
Necessary And Sufficient ◽  
Edge Theorem

Considered in this paper is the robust stability of a class of systems in which a relevant characteristic equation is a family of polynomials F: f(s, q) = a0(q) + a1(q)s + … + an(q)sn with its coefficients ai(q) depending linearly on q unknown-but-bounded parameters, q = (p1, p2, …, pq)T. It is known that a necessary and sufficient condition for determining the stability of such a family of polynomials is that polynomials at all the exposed edges of the polytope of F in the coefficient space be stable (the edge theorem of Bartlett et al., 1988). The geometric structure of such a family of polynomials is investigated and an approach is given, by which the number of edges of the polytope that need to be checked for stability can be reduced considerably. An example is included to illustrate the benefit of this geometric interpretation.

Robust stability analysis of LTI systems with fractional degree generalized frequency variables

2019 ◽  
Vol 22 (6) ◽  
pp. 1655-1674
Author(s):  
Cuihong Wang ◽  
Yan Guo ◽  
Shiqi Zheng ◽  
YangQuan Chen
Keyword(s):  
Robust Stability ◽  
Regulatory Networks ◽  
Linear Time ◽  
Exclusion Principle ◽  
Multi Agent Systems ◽  
System Matrix ◽  
Linear Time Invariant ◽  
Robust Stability Analysis ◽  
The Stability ◽  
Necessary And Sufficient

Abstract A novel linear time-invariant (LTI) system model with fractional degree generalized frequency variables (FDGFVs) is proposed in this paper. This model can provide a unified form for many complex systems, including fractional-order systems, distributed-order systems, multi-agent systems and so on. This study mainly investigates the stability and robust stability problems of LTI systems with FDGFVs. By characterizing the relationship between generalized frequency variable and system matrix, a necessary and sufficient stability condition is firstly presented for such systems. Then for LTI systems with uncertain FDGFVs, we present a robust stability method in virtue of zero exclusion principle. Finally, the effectiveness of the method proposed in this paper is demonstrated by analyzing the robust stability of gene regulatory networks.

ROBUST STABILITY OF MULTI-DIMENSIONAL (m-D) DISCRETE INTERVAL SYSTEMS AND APPLICATIONS

1991 ◽  
Vol 01 (01) ◽  
pp. 93-104 ◽  
Author(s):  
P. BAUER
Keyword(s):  
Robust Stability ◽  
Discrete Systems ◽  
Sufficient Condition ◽  
Invariant System ◽  
Necessary And Sufficient Condition ◽  
Interval System ◽  
Discrete Interval ◽  
The Stability ◽  
Necessary And Sufficient ◽  
Interval Systems

Robust stability of m-D discrete systems, represented by a m-D difference equation is analyzed. A sufficient condition for stability is derived, which requires the stability of one linear shift-invariant system. For special classes of systems, the stability of one corner of the interval system is a necessary and sufficient condition. The results are applicable to shift-variant and shift-invariant interval m-D systems. Applications and illustrative examples are also provided.

On the Necessary and Sufficient Conditions for the Stability of Linear Generalized Ordinary Differential, Linear Impulsive and Linear Difference Systems

2009 ◽  
Vol 16 (4) ◽  
pp. 597-616
Author(s):  
Shota Akhalaia ◽  
Malkhaz Ashordia ◽  
Nestan Kekelia
Keyword(s):  
Linear System ◽  
Difference Equations ◽  
Closed Interval ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Difference Systems ◽  
The Stability ◽  
Necessary And Sufficient ◽  
Generalized Ordinary Differential Equations ◽  
Lyapunov Sense

Abstract Necessary and sufficient conditions are established for the stability in the Lyapunov sense of solutions of a linear system of generalized ordinary differential equations 𝑑𝑥(𝑡) = 𝑑𝐴(𝑡) · 𝑥(𝑡) + 𝑑𝑓(𝑡), where and are, respectively, matrix- and vector-functions with bounded total variation components on every closed interval from . The results are realized for the linear systems of impulsive, ordinary differential and difference equations.

Some Structural Properties of Systolic Tree Automata

1989 ◽  
Vol 12 (4) ◽  
pp. 571-585
Author(s):  
E. Fachini ◽  
A. Maggiolo Schettini ◽  
G. Resta ◽  
D. Sangiorgi
Keyword(s):  
Structural Properties ◽  
Stability Problem ◽  
Sufficient Condition ◽  
Tree Automata ◽  
Necessary And Sufficient Condition ◽  
The Stability ◽  
Necessary And Sufficient

We prove that the classes of languages accepted by systolic automata over t-ary trees (t-STA) are always either equal or incomparable if one varies t. We introduce systolic tree automata with base (T(b)-STA), a subclass of STA with interesting properties of modularity, and we give a necessary and sufficient condition for the equivalence between a T(b)-STA and a t-STA, for a given base b. Finally, we show that the stability problem for T(b)-ST A is decidible.

scholarly journals Stability Analysis of Distributed Order Fractional Differential Equations

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
H. Saberi Najafi ◽  
A. Refahi Sheikhani ◽  
A. Ansari
Keyword(s):  
Stability Analysis ◽  
Characteristic Function ◽  
Differential Equations ◽  
Density Function ◽  
Robust Stability ◽  
Fractional Differential Equations ◽  
Stability Condition ◽  
Fractional Differential ◽  
The Stability ◽  
Distributed Order

We analyze the stability of three classes of distributed order fractional differential equations (DOFDEs) with respect to the nonnegative density function. In this sense, we discover a robust stability condition for these systems based on characteristic function and new inertia concept of a matrix with respect to the density function. Moreover, we check the stability of a distributed order fractional WINDMI system to illustrate the validity of proposed procedure.

scholarly journals Global Exponential Robust Stability of Static Interval Neural Networks with Time Delay in the Leakage Term

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Guiying Chen ◽  
Linshan Wang
Keyword(s):  
Neural Networks ◽  
Time Delay ◽  
Robust Stability ◽  
Sufficient Conditions ◽  
Leakage Term ◽  
Interval Neural Networks ◽  
Global Exponential Robust Stability ◽  
The Stability ◽  
Delay Differential ◽  
Delay Differential Inequality

The stability of a class of static interval neural networks with time delay in the leakage term is investigated. By using the method ofM-matrix and the technique of delay differential inequality, we obtain some sufficient conditions ensuring the global exponential robust stability of the networks. The results in this paper extend the corresponding conclusions without leakage delay. An example is given to illustrate the effectiveness of the obtained results.

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