Hierarchical Network Identification of Large-Scale Systems - An Approach Based on Dissipation Equalities

Abstract Recently, dynamical systems in science and engineering problems become increasingly larger and too complex. One of the ways to solve the difficulty is to model the systems with a hierarchically networked interconnection of subsystems. In this paper, we consider a hierarchical network system which is an interconnection of dissipative subsystems and identify both subsystems and network structure, called network system, preserving the dissipativity properties. We first estimate the state sequences of subsystems via the dissipation equalities instead of the matrix input-output equation in ordinary subspace identification methods. As a main result, we show an identification method in open-loop manner for subsystems and network systems based on the least-squares method. We also propose an identification method in a closed-loop manner.