Output-Feedback MRAC with Reference Model Tolerance of Nonlinearly Perturbed Delayed Plants

Paper i proceeding, 2011

A novel approach within the conventional MRAC framework for solving the problem of robust adaptive output tracking for a class of uncertain nonlinear dynamical systems with unknown timevarying state delays is proposed. A MRAC problem formulation in addition to the traditional asymptotic zero error tracking specification makes the problem statement contain an additional explicit requirement, namely the tracking objective is described by a set of admissible reference trajectories which is called a performance tube. As the design parameter which specifies the size of the performance tube, we select the reference model input signal than can be changed within specified bounds. An additional optimization task is formulated to find the best trajectory with a cost function that penalizes the deviation of the control signal from a given signal.