Outlier-Resistant Observer-Based Control for a Class of Networked Systems Under Encoding–Decoding Mechanism

This article is concerned with a new outlier-resistant observer-based control problem for a class of networked systems (NSs) under the encoding–decoding communication mechanism (EDCM). In order to lighten the communication burden and enhance the data security, the EDCM is introduced in the observer-to-controller channel. In case of the measurement outliers, a specific saturation function is adopted in the observer structure to restrain the abnormal innovations so as to mitigate the side effects brought from the outliers. The aim of this article is to design an observer-based controller, such that in the presence of measurement outliers, the closed-loop NS achieves the input-to-state stability (ISS) under the EDCM. By means of the uniform quantization technique, a criterion is first established in terms of the sizes of the encoding alphabet and the encoding period so as to ensure the detectability of the NS, and the requirement is also given on the capacity of the communication channel at each time instant. Then, with the help of ISS theory, the desired controller is obtained with its gain matrix parameterized by the solution to a certain inequality that can be solved via standard software packages. Finally, the effectiveness of the derived theoretical results is verified through three numerical simulation examples.

I. Introduction

Over the past several decades, networked systems (NSs) have received considerable research attention due to their prospective applications in various domains including, but are not limited to, unmanned aerial vehicles, remote diagnostics and troubleshooting, space and terrestrial exploration, and factory automation [4], [5], [11], [12], [14], [22], [25], [26], [29]–[31], [34], [36], [44]. In NSs, the information exchanges among actuators, sensors, controllers, and estimators/filters are executed over networked media such as wireless or distributed networks [13]. Comparing to the conventional point-to-point communication, the network-based communication enjoys a number of distinctive merits. For example, the introduction of network renders the effectiveness in eliminating unnecessary wiring between system components, which indicates that the complexity and overhead of the corresponding system can be significantly diminished. Moreover, when some system components are required to be added/removed, NSs can be easily modified or upgraded without causing major changes in the system structure.