Prescribed-Time Control of Nonlinear Systems With Unknown Coefficients: An Event-Triggered Approach

This work considers the prescribed-time control problem of uncertain nonlinear systems with unknown control coefficients via an event-triggering strategy. In contrast to existing event-based prescribed-time works where the control coefficients are supposed to be known, in this work, not only the magnitude but also the sign of the control coefficient is allowed to be unknown. Based on a newly established Nussbaum-type lemma, the underlying problem is addressed by proposing an adaptive prescribed-time control scheme, which is characterized by the joint design of the triggering condition and actual controller. Moreover, the developed control scheme enables the execution time to be extended to infinity, distinguishing itself from those where the valid execution time can only be finite (ended at the prescribed time). It is proved that the closed-loop signals are globally bounded and system states converge to the origin within a prespecified time. Besides, the Zeno-free behavior is ensured. A robotic manipulator is exploited to demonstrate the validity of the theoretical findings.