Prescribed performance control of strict-feedback systems under actuation saturation and output constraint via event-triggered approach

In this work, we study the performance-guaranteed event-triggered control for a class of uncertain nonlinear systems in strict-feedback form subject to input saturation and output constraint. The prescribed performance (ie, convergence rate, tracking error accuracy) and output constraint are firstly taken into account for nonlinear systems with event-triggered input. By blending a speed transformation into the barrier Lyapunov function and introducing an intermediate variable to the system, two different event-triggered control schemes are proposed for systems with and without saturation, respectively. Each scheme has two rules to determine triggering time sequences, one for control signal updating and the other for control signal transmission with the latter being a subsequence of the first. Meanwhile, it is proved that the tracking error converges to a preset compact set around zero at the prescribed decay rate and the output is maintained within a given bound at all times. Simulation verification also confirms the effectiveness of the proposed approach.