Prescribed-Time Control of Nonlinear Systems With Unknown Coefficients: An Event-Triggered Approach
针对控制系数大小和符号均未知的不确定非线性系统，提出一种自适应预设时间控制方案，通过事件触发策略确保系统状态在指定时间内收敛到原点，且执行时间可无限延长。
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.