• Journal of the Korean Society of Safety
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• v.7 no.4
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• pp.101-104
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• 1992

It is shown that for a characteristic equation of continuous linear system, stability can be determined by conditions srggested in this paper. And also It Is of interest to Know how much coefficients of the low-order characteristic equation(N$\leq$5) can be perturbed while simutanously preserving the stable condition of the equation. This result is analogous to result by Anderson et al. based on the Kharitonov's conditions and Hermite - Biehler theorem.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.5-9
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• 1995

In many cases of robust stability problems, the characteristic polynomial has real coefficients which or nonlinear functions of uncertain parameters. For this set of polynomials, a new stability easily checking algorithm for reducing the conservatism of the stability bound are given. It is the new stability theorem to determine the stability region just in parameter space. Illustrative example show that the presented method has larger stability bound in uncertain parameter space than others.

• Journal of Power Electronics
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• v.9 no.1
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• pp.61-67
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• 2009

In this paper, a simple technique is presented for robust stability testing of perturbed DC-DC converters having multi-linear uncertainty structure. This technique provides a necessary and sufficient condition for testing robust stability. It is based on the corollary of Routh criterion and gridding of parameters. The previous work based on parametric control theory using Kharitonov's theorem and Hermite Biehler theorem gives conservative results and only the sufficient condition of stability, whereas the proposed method provides the necessary and sufficient condition for testing robust stability and it is computationally efficient. The superiority of the method is compared with the Edge theorem.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.5
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• pp.323-330
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• 2004

In this paper, we propose a design method of PID controller using an improved Tabu Search. Tabu Search is improved by neighbor solution creation using Gaussian random distribution and generalized Hermite Biehler Theorem for stable bounds. The range of admissible proportional gains are determined first in closed form. Next the optimal PID gains are selected by improved Tabu Search. The results of Computer simulations represent that the proposed Tabu Search algorithm shows a fast convergence speed and a good control performance.