Heterogeneous string stability of unidirectionally interconnected MIMO LTI systems

String Stability of Interconnected Systems - Automatic Control, IEEE Transactions on

In this paper we introduce the notion of string stability of a countably infinite interconnection of a class of nonlinear systems. Intuitively, string stability implies uniform boundedness of all the states of the interconnected system for all time if the initial states of the interconnected system are uniformly bounded. It is well known that the input-output gain of all the subsystems less tha...

String Stability Analysis of Homogeneous Linear Unidirectionally Connected Systems with nonzero Initial Conditions

This paper investigates string stability issues in homogeneous strings of strictly proper feedback control systems. We consider initial condition problems with unidirectional nearest neighbour communications, using only linear systems with two integrators in the loop. We define string stability as a type of stability that is uniform with respect to the string length. We show conditions under wh...

LMI conditions for robust adaptive control of MIMO LTI systems

Pole-free control designs for nonsquare LTI MIMO systems

This paper presents (structurally stable) pole-free control designs for minimum variance control (MVC) and generalized minimum variance control (GMVC). For MVC, the authors’ general approach to pole-free design, that is the Smith-factorization approach, is advocated. For GMVC, a numerical optimization procedure is used in order to minimize the sum of modules of all poles of the closed-loop GMVC...

Feedback-Based Iterative Learning Control for MIMO LTI Systems

This paper proposes a necessary and sufficient condition of convergence in the 2 L norm sense for a feedback-based iterative learning control (ILC) system including a multi-input multi-output (MIMO) linear time-invariant (LTI) plant. It is shown that the convergence conditions for a nominal plant and an uncertain plant are equal to the nominal performance condition and the robust performance co...