Stabilisation of discrete-time interconnected systems under control constraints

The problem of stabilising a discrete-time large-scale uncertain system where the norms of the decentralised controls are bounded by prespecified constants is considered. The uncertainty is supposed to be cone-bounded, but not necessarily matched. A nonlinear controller is proposed, which guarantees the exponential stability of the whole system, if the bounds of uncertainties are not too large. If the nominal part of the subsystems is nonlinear, the nominal free system is supposed to be exponentially stable. If the nominal system is linear and time invariant, this assumption can be omitted and substituted by controllability.