Multichannel Linear Time-invariant Systems Research Articles

Fault-tolerant decentralized H-infinity control for multi-channel systems using homotopy method

This paper considers a fault-tolerant decentralized H-infinity control problem for multi-channel linear time-invariant systems. The purpose is to design a decentralized H-infinity output feedback controller to stabilize the given system and achieve a certain H-infinity performance requirement both in the normal situation and in the situation where any one of the local controllers fails. The designed problem is reduced to a feasibility problem of a set of bilinear matrix inequalities (BMIs). An algorithm is proposed to solve the BMIs. First, the normal situation is considered where all the local controllers are functioning. The local controllers are obtained from a standard centralized H-infinity controller by using a homotopy method imposing a structural constraint progressively. Secondly, the above case is extended to the one where any one of the local controllers fails. We again use a homotopy method where the coefficient matrices of the failed controller are decreased progressively to zero. The efficiency of the proposed algorithm is demonstrated by an example.

Decentralized H∞ controller design: a matrix inequality approach using a homotopy method

This paper considers a decentralized H ∞ control problem for multi-channel linear time-invariant systems. Our interest is focused on dynamic output feedback. The control problem is reduced to a feasibility problem of a bilinear matrix inequality (BMI). The objective of this paper is to propose an algorithm for solving the BMI by using the idea of the homotopy method, where the controller's coefficient matrices are deformed from full matrices defined by a centralized H ∞ controller, to block-diagonal matrices of specified dimensions which describe a decentralized H ∞ controller. When a feasible decentralized H ∞ control problem is considered, it can be expected that there always exists a centralized H ∞ controller for which the algorithm converges and presents a desired solution. To find such a suitable centralized H ∞ controller, random search in a parametrized set of H ∞ controllers with a proper dimension is suggested. The efficiency of the proposed algorithm is demonstrated by an example.

Iterative algorithms based on multistage criteria for multichannel blind deconvolution

Blind deconvolution and blind equalization have been important interesting topics in diverse fields including data communication, image processing, and geophysical data processing. Recently, Inouye and Habe introduced a multistage criterion for attaining blind deconvolution of multiple-input multiple-output (MIMO) linear time-invariant (LTI) systems. In this correspondence, based on their criterion, we present iterative algorithms for solving the blind deconvolution problem of MIMO LTI systems. However, their criterion should be subjected to several constraints of equations. Therefore, they proposed a new constraint-free multistage criterion for accomplishing the blind deconvolution of MIMO LTI systems. Based on their unconstrained criterion, we show iterative algorithms for solving the blind deconvolution of multichannel LTI systems.

Decentralized H∞ Controller Design: A Matrix Inequality Approach Using a Homotopy Method

This paper considers a decentralized H∞ control problem for multichannel linear time-invariant systems. Our interest focuses on dynamic output feedback. The control problem is reduced to a feasibility problem of a bilinear matrix inequality (BMI). To solve the BMI, an algorithm is proposed using the idea of the homotopy method, where the controller's coefficient matrices are deformed from full matrices defined by a centralized Hoo controller to block-diagonal matrices of specified dimensions describing a decentralized H∞ controller.

Multistage Criteria for Blind Deconvolution of Multichannel Linear Time-Invariant Systems

Abstract Blind deconvolution and blind equalization have been important interesting topics in diverse field including data communication, image processing and geophysical data processing. Recently, Inouye and Habe proposed a constrained multistage criterion for attaining blind deconvolution of multichannel linear time-invariant (LTI) systems (Inouye and Habe, 1995). In this paper, based on their constrained criterion, we present two iterative algorithms for solving the blind deconvolution problem of multichannel LTI systems. Inouye and Sato proposed a new unconstrained multistage criterion for accomplishing the blind deconvolution of multichannel LTI systems (Inouye and Sato, 1996). Based on their unconstrained criterion, we show an iterative algorithm for solving the blind deconvolution of multichannel LIT systems. Simulation examples are included to examine the proposed algorithms.