Event-Triggered Guaranteed Performance Control of Nonaffine Uncertain Nonlinear Systems via Intermittent Feedback

This paper addresses the event-triggered adaptive control problem with prescribed performance guarantees for a class of nonaffine uncertain nonlinear systems. Compared with existing works, intermittent communication in the sensor-to-controller channel for high-order nonaffine nonlinear systems is considered. Since the controller design involves intermittent variables arising from the event triggers in the sensor-to-controller channel and completely unknown nonaffine nonlinearities, traditional control schemes encounter significant challenges and usually render intricate controllers. To alleviate these complexities, a system transformation is involved to convert the system into an affine-like form, followed by a performance transformation independent of initial conditions, thus enabling the proposed method to encompass a wide range of such problems. Unlike traditional backstepping-based methods, a non-recursive control approach with an observer is employed in this work, which simplifies both controller and event-triggered mechanism design. It is theoretically proven that all signals in the closed-loop system are uniformly ultimately bounded, and the event-triggered scheme significantly reduces the communication burden while precluding the Zeno phenomenon. Simulation examples are provided to demonstrate the effectiveness of the proposed method.
Note to Practitioners
—This work is motivated by the control desiderata, including computational and communication resources efficiency, transient performance guarantees, and adaptability to the uncertain nonlinear, which emerge in the networked control systems, such as unmanned aerial vehicles, robot manipulators, and chemical processes. Although numerous works have been reported to solve part of these problems, there is no unified solution covering these control objectives. In this paper, we propose an event-triggered guaranteed performance control via intermittent feedback signals in a unified framework, which is applicable to a wide class of applications without controller redesign. The intermittent communication in the sensor-to-controller channel is co-designed with the adaptive controller, which provides a provable sampling scheme for the digital implementation of nonlinear networked control systems. The proposed method permits flexible performance specifications, including exponential and prescribed-time types, rather than theoretical asymptotic behavior, lending it readily to engineering purposes. Furthermore, the performance functions are designed to be independent of the initial error, eliminating the need for recalibration that hinders practical applications. The non-recursive controller with intermittent feedback and adaptive updates reduces both the communication and computation burdens, which is simple yet efficient, making our approach user-friendly and less demanding in practical applications.