Random Access Communication for Wireless Control Systems with Energy Harvesting Sensors

TL;DR

This paper proposes a random access communication strategy for energy harvesting wireless control systems, optimizing transmission probabilities to ensure control stability despite shared channels and energy constraints.

Contribution

It introduces an adaptive, stochastic dual-based scheduling method for energy harvesting sensors in wireless control, with theoretical stability guarantees and practical numerical validation.

Findings

Optimal transmission probability adapts to plant, channel, and battery states.

Decoupled sensor scheduling via stochastic dual method.

Guarantees on control system stability under random access.

Abstract

In this paper, we study wireless networked control systems in which the sensing devices are powered by energy harvesting. We consider a scenario with multiple plants, where the sensors communicate their measurements to their respective controllers over a shared wireless channel. Due to the shared nature of the medium, sensors transmitting simultaneously can lead to packet collisions. In order to deal with this, we propose the use of random access communication policies and, to this end, we translate the control performance requirements to successful packet reception probabilities. The optimal scheduling decision is to transmit with a certain probability, which is adaptive to plant, channel and battery conditions. Moreover, we provide a stochastic dual method to compute the optimal scheduling solution, which is decoupled across sensors, with only some of the dual variables needed to be shared between nodes. Furthermore, we also consider asynchronicity in the values of the variables across sensor nodes and provide theoretical guarantees on the stability of the control systems under the proposed random access mechanism. Finally, we provide extensive numerical results that corroborate our claims.