Papers by Keyword: Linear System

Abstract: An optimization algorithm method design and analysis is presented for class of linear uncertain systems. Firstly, it is shown that disturbances of linear uncertain systems are divided two parts by the projection matrix, one is matched and the other is unmatched part. Then the controller based on integral sliding mode and optimization performance index is constructed to ensure the robustness of the linear uncertain systems. Additionally, we give an optimization performance guaranteeing the stability of proposed procedure by using the Lyapunov theory. Simulations show the effectiveness of the method proposed that a linear system is best controlled by a linear controller.

Abstract: In this paper, a novel framework of robust observer for linear system with parametric uncertain state matrix matched with output matrix is introduced. The scheme is derived by including an extra term to the feedback gain, and the term is obtained by the analysis of the Lyapunov stability theory and LMI (Linear Matrix Inequality). The proposed observer is less conservative and thus lead to a low gain matrix based on the novel framework. Finally, the effectiveness of the proposed method is validated by the numerical simulations on Matlab environment.

Abstract: This paper studies the output-feedback model reference robust control for MIMOlinear systems with generalized relative degree one. A new robust controlscheme is proposed within the framework of model reference control. Under theassumption that the high-frequency gain matrix of the plant can be transformedto a glass of main diagonal dominant matrix via full rank transformation, it isshown that all signals of the closed-loop system are globally uniformly boundedand meanwhile, the tracking errors converge to a residual set that can be madearbitrarily small by properly choosing some design parameters. Simulationresults are presented to illustrate the effectiveness of the proposed scheme.

Abstract: For a given matrix function, determining whether it meets the conditions of the state transition matrix by utilizing the criteria of the state transition matrix. If satisfied, three computing methods of systematic matrix is deduced through both qualities and relationship with the systematic matrix of the state transition matrix, comparing the characteristics of every method and inspecting availability of each solving method. Finally, the simple way for solving systematic matrix is obtained, which provides reference for solving systematic matrix in practice.

Abstract: An over-damped second-order linear system with fluctuant coefficient of the second-order derivative and signal-modulated noise is considered. Based on linear-system theory, the expression of the output amplitude is obtained. Analytical results shows that the output amplitude is a non-monotonic function of the noise strength, and it varies non-monotonously with the increase of the system parameter a and b, while it decreases monotonously with the increase of the signal frequency and the system parameter c.

Abstract: This article described a novel type of autonomous underwater vehicle and modeled the dynamics. This kind of vehicle looked like an air-plane with large wings and worked under the condition of negative buoyancy. The motions of negative-buoyancy-vehicle (NBV) in the longitudinal plane were analyzed through linear system theory. This paper divided motion of NBV into a few modes in the longitudinal plane and provided a method of reduction of order to simplify the analysis, as well as gave the criterion of static stability under constant load in longitudinal plane. It had been found that the maneuverability and stability of NBV was related to many factors such as the velocity, lift-drag ratio, buoyancy and metacentric height. All of the conclusions could be applied on NBV design.

Abstract: A model simplification method for linear discrete systems is presented to determine both numerator and denominator coefficients of a simplified model by differential evolution algorithm in order to minimize the root mean squared error between the step responses of original and simplified models. The performance of the proposed method was demonstrated by two examples with different orders and the results show that the method can yield a good approximation of the original system.

Abstract: The purpose of this paper is to discuss the stability of linear system with constant coefficients. A simple practical criterion for the stability of linear system with constant coefficients is obtained.