Sampled-Data-Based Event-Triggered Active Disturbance Rejection Control for Disturbed Systems in Networked Environment

Abstract

This paper develops a methodology on sampled-data-based event-triggered active disturbance rejection control (ET-ADRC) for disturbed systems in networked environment when only using measurable outputs. By using disturbance/uncertainty estimation and attenuation technique, an event-based sampled-data composite controller is proposed together with a discrete-time extended state observer. Under the presented new framework, the newest state and disturbance estimates as well as the control signals are not transmitted via the common sensor-controller network, but instead communicated and calculated until a discrete-time event-triggering condition is violated. Compared with the periodic updates in the traditional time-triggered active disturbance rejection control, the proposed ET-ADRC scheme can remarkably reduce the communication frequency while maintaining a satisfactory closed-loop system performance. The proposed discrete-time control scheme provides the engineers with a manner of direct and easier implementation via networked digital computers. It is shown that the bounded stability of the closed-loop system can be guaranteed. Finally, an application design example of a dc-dc buck converter with experimental results is conducted to illustrate the efficiency of the proposed control scheme.

Event‐triggered observer‐based robust H∞ control for networked control systems with unknown disturbance

“…Yet, along with these advantages, some challenging issues (bandwidth allocation, communication delay, packet dropouts, packet disorders, and channel fading) emerged and gave rise to much attention. Then most recently, the research on the NCSs has become a heated topic and many elegant results have been proposed . For instance, in Reference , an optimal linear filter for the NCSs was designed with involving time‐correlated fading channels.…”

“…Up until now, some effective approaches have been reported, such as time‐triggered strategy, event‐triggered scheme (ETS), and hybrid‐triggered one . Unlike the time‐trigger, since the ETS can be more efficient in reducing the number of transmitted data, thus recently, plenty of event‐based techniques have been proposed to study various control systems including the NCSs . In Reference , a controller design on the combination of three matrices Q, S, R (QSR)‐dissipativity was proposed by using a continuous‐time ETS, in which Zeno behaviors could be avoided.…”

“…Since the disturbances are ubiquitous and usually degrade control performances or even result in instability, a large number of antidisturbance control methods have been reported in order to improve the robustness . In References and , the adaptive control and output feedback one were, respectively, studied by using disturbance‐observer method.…”

“…Especially to achieve noise suppression and disturbance attenuation, Reference utilized a modified DOBC structure to propose the robust controller. Meanwhile, since the disturbances widely exist in communication networks, many methods have been proposed to study the disturbed NCSs . In Reference , by utilizing robust adaptive sliding mode control, an observer was designed to estimate the disturbance in switching NCSs.…”

“…Especially as for network‐based multiagents, a self‐tuning adaptive distributed observer was proposed to ensure the cooperative output regulation . Most recently, some event‐triggered approaches have been utilized to study the NCSs by using disturbance observer methods . In Reference , the state estimation was investigated and an event‐based observer was presented to estimate the total disturbance.…”