Prescribed Performance Output Feedback Control: An approximate passivation approach

In this paper we address the Prescribed Performance Control problem for uncertain MIMO systems, through output feedback. In order to do so, we exploit the feedback passivation approach according to which a system is rendered passive with the use of an output feedback control law. Using a two phase controller design procedure we guarantee convergence of the output tracking error to a predefined arbitrarily small residual set, with rate no less than a prespecified value, exhibiting a maximum overshoot less than a sufficiently small constant. Moreover, all other signals in the closed loop are kept bounded. To avoid possible division by zero, the output feedback passivation controller is of switching type.