System types in feedback control with saturating actuators

This note extends the classical notion of system type to feedback control with saturating actuators. For step, ramp, and parabolic inputs, it defines the so-called trackable domains and evaluates steady-state errors. It shows that, unlike the linear case, the role of the poles at the origin of the plant and the controller are different and, on this basis, extends the notion of system type. In addition, the related notion of system type with respect to disturbances is discussed and extended to systems with saturating actuators.