Multiple model adaptive control with safe switching (Q2763361)

Adaptive control of a partially unknown plant is investigated. It is assumed that the plant belongs to a given finite set of nominal plants or is close to a member of this set. To each nominal plant a nominal controller is associated. The nominal plants and the controllers are linear and time invariant. For switching among the controllers a ``multi estimator'' driven by the plant input and the plant output is developed. The outputs of the multi estimator correspond to the nominal plants and match if the unknown plant is equal to the nominal plant. A switching logic based on frequency-dependent performance measures decides which controller is implemented. For safe switching the frozen plant-controller combination must be never unstable.NEWLINENEWLINENEWLINETwo switching methods based on different performance measures are proposed. The methods are demonstrated by an example. The plant to be controlled is described by a third-order transfer function with a non-minimum-phase zero. The results obtained by simulation are discussed in detail.