Dynamic Event-Triggered Fixed-Time Tracking Control for State-Constrained Nonlinear Systems With Dead Zone Based on Fast Fixed-Time Filters
针对具有状态约束和死区的非线性系统，提出一种动态事件触发固定时间跟踪控制方法，通过状态变换和快速固定时间滤波器解决约束和死区问题，并节省通信资源。
In this article, the problem of event-triggered fixed-time tracking control for nonlinear systems with state constraints and dead zone is considered. First, for state-constrained problems, the state transformation technique is applied to remove the restriction that the virtual control input needs to satisfy the “feasibility condition.” Second, to deal with dead zone, fixed-time compensation filters are introduced. Different from the existing compensating filters, the proposed filter can make the filter state converge faster to better eliminate the effect of dead zone by introducing higher-order terms of the filter state. To avoid the “explosion of complexity” problem inherent in backstepping, fast fixed-time filters (FFTFs) are developed. Unlike the existing first-order filters and fixed-time filters (FTFs), the proposed filters can achieve faster convergence of the filtering state. Unlike the existing dynamic event-triggered mechanism (DETM), the proposed improved DETM has larger event-triggered intervals (ETIs) and is more resource-saving, by adding two dynamic variables adjusted by historical triggered information. Furthermore, the proposed control scheme guarantees that: all states are within constraints, all closed-loop system signals are bounded, and tracking error converges to an arbitrarily small neighborhood of the origin in a fixed time. Finally, a jerk circuit system verifies the efficacy of the proposed method.