Decentralized control with input saturation: a first step toward design

This article summarizes important observations about control of decentralized systems with input saturation and provides a few examples that give insight into the structure of such systems

Towards a minimal order distributed observer for linear systems

In this paper we consider the distributed estimation problem for continuous-time linear time-invariant (LTI) systems. A single linear plant is observed by a network of local observers. Each local observer in the network has access to only part of the output of the observed system, but can also receive information on the state estimates of its neigbours. Each local observer should in this way generate an estimate of the plant state. In this paper we study the problem of existence of a reduced order distributed observer. We show that if the observed system is observable and the network graph is a strongly connected directed graph, then a distributed observer exists with state space dimension equal to $Nn - \sum_{i =1}^N p_i$, where $N$ is the number of network nodes, $n$ is the state space dimension of the observed plant, and $p_i$ is the rank of the output matrix of the observed output received by the $i$th local observer. In the case of a single observer, this result specializes to the well-known minimal order observer in classical observer design.Comment: 12 pages, 1 figur

Decentralized optimal control in descriptor systems

Application of Matrix Minimum Principle to a linear decentralized optimal control in descriptor systems is studied in this thesis. Linear-quadratic index of performance with Gaussian initial state is considered. The necessary and sufficient conditions for optimality are derived An additional constraint is imposed such that the controllers are linear function of output y(t) rather than of the state vector x(t). The optimal gain matrix Gi* is then specified by the necessary conditions. Two examples are developed to illustrate the concept

Structural Completeness of a Multi-channel Linear System with Dependent Parameters

It is well known that the "fixed spectrum" {i.e., the set of fixed modes} of a multi-channel linear system plays a central role in the stabilization of such a system with decentralized control. A parameterized multi-channel linear system is said to be "structurally complete" if it has no fixed spectrum for almost all parameter values. Necessary and sufficient algebraic conditions are presented for a multi-channel linear system with dependent parameters to be structurally complete. An equivalent graphical condition is also given for a certain type of parameterization

Decentralized control and periodic feedback

Cataloged from PDF version of article.The decentralized stabilization problem for linear, discretetime, periodically timevarying plants using periodic controllers is considered. The main tool used isl the technique of Uning a periodic system to a timeinvariant one via extensions of the input and output spaces. It is shown that a periodically time-varying system of fundamental period N can be stabilized by a decentralized periodic controller if and only if: 1) the system is stabilizable and detectable, and 2) the N-lifting of each complementary subsystem of identieally zero inpnt-ontput map is free of unstable input-output decoupling zeros. In the special case of N = 1, this yields and clarifies all the mr exisling results on decentralized stabilization of time-invariant plants by periodically time varying controllers