Robust and perfect tracking control of a DC servo motor

Robust and perfect tracking (RPT)
approach enable engineers to design low-order model-
based controllers, which result in closed-loop systems
that are able to yield fast tracking of target references
with small overshoot. In fact, an RPT controller’s
performance can be adjusted using a single positive
scalar tuning parameter, say ϵ, which guarantees
internal stability of the closed-loop system and yields
arbitrary fast settling time in the faces of external
disturbances and initial conditions as long as control
signal is free from physical constraints. In reality,
physical constraints must be considered, and hence,
arbitrary fast tracking can never be achieved.
This paper presents the design of a closed-form
parameterized two-degree-of-freedom (2DOF)
integrating controller using RPT approach for a DC
servo motor application. The simulation and experimental results show that
the closed-loop system using the RPT controller yields
better positioning performance as measured by the
settling time. In addition, the closed-loop system with
the RPT controller has larger stability margins and lower
sensitivity compared with the system using the PID
controller.