An Analysis on Stabilizability and Reliability Relationship in Wireless Networked Control Systems

TL;DR

This paper introduces a probabilistic measure of stabilizability in wireless networked control systems, linking communication reliability with system stability, and provides a closed-form expression to quantify this relationship.

Contribution

It is the first to incorporate stochastic channel parameters into the analysis of asymptotic stabilizability using a probabilistic approach.

Findings

Derived a closed-form expression for stabilizability probability.

Showed how communication reliability impacts system stability.

Numerical results illustrate parameter effects on stabilizability.

Abstract

The stabilizability of wireless networked control systems (WNCSs) is a deterministic binary valued parameter proven to hold if the communication data rate is higher than the sum of the logarithm of unstable eigenvalues of the open-loop control system. In this analysis, it is assumed that the communication system provides a fixed deterministic transmission rate between the sensors and controllers. Due to the stochastic parameters of communication channels, such as small-scale fading, the instantaneous rate is an intrinsically stochastic parameter. In this sense, it is a common practice in the literature to use the deterministic ergodic rate in analyzing the asymptotic stabilizability. Theoretically, there exists no work in the literature investigating how the ergodic rate can be incorporated into the analysis of asymptotic stabilizability. Considering the stochastic nature of channel parameters, we introduce the concept of probability of stabilizability by interconnecting communication link reliability with the system's unstable eigenvalues and derive a closed-form expression that quantifies this metric. Numerical results are provided to visualize how communication and control systems' parameters affect the probability of stabilizability of the overall system.