  Feedback control laws have been traditionally implemented in a periodic
fashion on digital hardware. Although periodicity simplifies the analysis of
the mismatch between the control design and its digital implementation, it also
leads to conservative usage of resources such as CPU utilization in the case of
embedded control. We present a novel technique that abandons the periodicity
assumption by using the current state of the plant to decide the next time
instant in which the state should be measured, the control law computed, and
the actuators updated. This technique, termed self-triggered control, is
developed for two classes of nonlinear control systems, namely, state-dependent
homogeneous systems and polynomial systems. The wide applicability of the
proposed results is illustrated in two well known physical examples: a jet
engine compressor and the rigid body.
