  Delayed feedback control is an easy realizable control method which generates
control force by comparing the current and the delayed version of the system
states. In this paper, a new form of the delayed feedback structure is
introduced. Based on the proposed delayed feedback method, a new robust
tracking system is designed. This tracking system improves the features of the
conventional state feedback with integral action and it is also able to reject
higher order disturbances compared to the conventional method. In addition, the
proposed tracking system tracks the ramp-shape reference input signal as well,
which this is not possible through the conventional state feedback. Due to easy
implementable feature of the proposed delayed feedback tracking system, it can
be used in practical applications effectively. Moreover, since the proposed
method adds delays to the closed loop system dynamics, the ordinary
differential equation of the system changes to a delay differential equation
with an infinite number of characteristic roots. Thus, conventional pole
placement procedures cannot be used to design the delayed feedback controller
parameters and place the unstable roots in the left half plane. In this paper,
the simulated annealing algorithm is used to determine the proposed control
system parameters and move the unstable roots of the delay differential
equation to the left half plane. Finally, the efficiency of the proposed
reference input tracker is demonstrated on a case study.
