On the GPI-sliding mode control of switched fractional order systems

The control of a special class of single input single output (SISO) switched fractional order systems (SFOS) is addressed from the viewpoints of the generalized proportional integral (GPI) feedback control approach and a sliding mode based Sigma - Delta modulation implementation of an average model based designed feedback controller. A fractional order GPI controller is proposed which transforms the average model of the system into a pure, integer order, chain of integrations with desired closed loop dynamics achieved through a classical compensation network robustly acting in the presence of constant load perturbations. A sliding mode based Sigma - Delta modulation implementation of the continuous, bounded, dynamic average output feedback control signal is adopted for the switched system. An illustrative simulation example dealing with an electric radiator system is presented