Minimization of Energy Consumption Per Bit Using an Average Dwell-Time Approach for Wireless Networked Control Systems

Rafaela Scaciota,Richard Demo Souza,Glauber Brante,Guilherme Luiz Moritz

doi:10.1109/access.2019.2923961

Abstract

We study the energy consumption of the communication links in a wireless networked control system, where sensors and actuators exchange information using a wireless channel. Our purpose is to minimize the energy consumption, assuming that the sensors and actuators may be battery-powered devices, without affecting the control system stability, which may be impacted by communication errors. As a consequence, the stability of the control system can be related to the switching time between stable and unstable subsystems. By resorting to a communication-control co-design approach, we obtain a closed-form expression for the optimal outage probability related to the system stability, which is then employed as a constraint to adapt the transmit power and the bit rate in order to minimize the energy consumption. Our results show a decreased energy consumption when compared to the traditional optimization approach in wireless communications, which is to treat communication and control systems independently, fixing the outage probability according to a reliability constraint, not necessarily linked to the stability.

Highlights

In the decade, the manufacturing industry is expected to evolve toward a distributed organization
wireless networked control systems (WNCSs) are feedback systems composed of spatially distributed sensors, actuators, and controllers communicating through wireless links instead of point-to-point wired connections [3]
By defining a mathematical optimization problem in order to minimize the energy consumption per transmitted bit of the WNCS, we find the optimal transmission power to be employed by sensors and controllers;

Summary

Introduction

The manufacturing industry is expected to evolve toward a distributed organization. Under the concept of the Industry 4.0, the production will be empowered by communication abilities, which will enable low-energy and flexible manufacturing processes, sharing resources in order to optimize the production chain, proving better integration with logistics [1]. In this context, 5G networks will be key enablers, providing the required communication infrastructure. WNCSs are feedback systems composed of spatially distributed sensors, actuators, and controllers communicating through wireless links instead of point-to-point wired connections [3]. Low energy consumption is a primary goal in battery-operated networks, which is the case for a multitude of factory automation applications like safety systems, closed loop regulatory and supervisory systems [5]

Objectives

Results

Conclusion