Deterministic control of large-scale uncertain dynamical systems (Q1088618)

The paper considers global practical stabilization of interconnected systems with time-varying uncertainties using decentralized control. The local controls consist of linear state feedback which stabilizes the subsystems in the absence of uncertainties plus a nonlinear feedback to take care of the uncertainties. Stability condition for the overall system is stated in terms of the principal minors of an aggregate test matrix whose diagonal elements represent the degree of stability of the subsystems and the off-diagonal ones the strength of interconnections. If stability cannot be achieved by local controls only, then for each subsystem additional feedback from the neighboring systems (i.e., global control) is used to counter the destabilizing effect of interconnections. Such a control scheme guarantees global practical stability provided the interconnections satisfy the so called matching conditions.