Stabilisation of discrete-time interconnected systems under control constraints

The problem of stabilising a discrete-time large-scale uncertain system whe re the norms of the decentralised controls are bounded by prespecified cons tants is considered. The uncertainty is supposed to be cone-bounded but not necessarily matched. A nonlinear controller is proposed which guarantees t he exponential stability of the whole system, if the bounds of uncertaintie s are not too large. If the nominal part of the subsystems is nonlinear, th e nominal free system is supposed to be exponentially stable. If the nomina l system is linear and time invariant, this assumption can be omitted and s ubstituted by controllability.