Feedback error learning control without recourse to positive realness

Feedback error learning (FEL) method has been proposed by Kawato et al. as a scheme of brain motor control in neurophysiology. Recently, Miyamura and Kimura have established a control theoretical validity of the FEL method in the framework of adaptive control and proved its stability based on the strictly positive realness. In this note, we propose another scheme for the feedback error learning method which does not require any positive real conditions.