  The paper proposes a novel event-triggered control scheme for nonlinear
systems based on the input-delay method. Specifically, the closed-loop system
is associated with a pair of auxiliary input and output. The auxiliary output
is defined as the derivative of the continuous-time input function, while the
auxiliary input is defined as the input disturbance caused by the sampling or
equivalently the integral of the auxiliary output over the sampling period. As
a result, a cyclic mapping forms from the input to the output via the system
dynamics and back from the output to the input via the integral. The
event-triggering law is constructed to make the mapping contractive such that
the stabilization is achieved and an easy-to-check Zeno-free condition is
provided. With this idea, we develop a theorem for the event-triggered control
of interconnected nonlinear systems which is employed to solve the
event-triggered control for lower-triangular systems with dynamic
uncertainties.
