ASPR based adaptive output tracking control with adaptive parallel feedforward compensator and its validation through experiments

This paper provides an almost strictly positive real (ASPR) based adaptive output tracking control system design strategy. A design scheme of adaptive output feedback based output tracking control system with an adaptively adjusting parallel feedforward compensator is presented. An adaptive parallel feedforward compensator (PFC) is introduced for non-ASPR systems in order to guarantee the ASPR-ness of the controlled system and maintain the stability of the designed adaptive output feedback control system. The introduced PFC parameters are adaptively adjusted to remain the ASPR-ness of the resulting augmented system. Furthermore, an adaptive NN feedforward control is added to attain the output tracking. The stability of the resulting control system is analyzed theoretically and the effectiveness of the proposed method is confirmed through experiments on a magnetic levitation system.