Decentralized Indirect Adaptive Control of Interconnected Systems

Continuous time decentralized indirect adaptive controllers are proposed for a large scale system composed of N interconnected linear subsystems with unknown parameters. Each local adaptive law utilises a normalising signal which is generated using the local input and the outputs of all the subsystems. Sufficient conditions for the closed loop stability of the adaptively controlled large scale system are derived. These conditions provide bounds on the size of the allowable unmodelled interconnections and suggest ways to effect an improvement in the latter by appropriately choosing the free parameters of the local adaptive controllers.