  This paper presents a control technique for output tracking of reference
signals in continuous-time dynamical systems. The technique is comprised of the
following three elements: (i) output prediction which has to track the
reference signal, (ii) a controller based on an integrator with variable gain,
and (iii) a speedup of the control action for enhancing the tracker's accuracy
and, in some cases, guaranteeing stability of the closed-loop system. The
technique is suitable for linear and nonlinear systems, implementable by simple
algorithms, can track reference points as well as time-dependent reference
signals, and may have large, even global domains of attraction. The derived
theoretical results include convergence of the tracking controller and error
analysis, and are supported by illustrative simulation and laboratory
experiments.
