Feedback Scheduling of Priority-Driven Control Networks

TL;DR

This paper introduces a feedback scheduling approach for priority-driven control networks to dynamically allocate bandwidth, significantly improving quality-of-control in variable network conditions.

Contribution

It presents an integrated feedback scheduler combining sampling period adjustment and priority modification for real-time QoC management in control networks.

Findings

Significant QoC improvement over open-loop scheduling.

Effective under both underloaded and overloaded network conditions.

Feasible implementation due to inherent priority-driven network characteristics.

Abstract

With traditional open-loop scheduling of network resources, the quality-of-control (QoC) of networked control systems (NCSs) may degrade significantly in the presence of limited bandwidth and variable workload. The goal of this work is to maximize the overall QoC of NCSs through dynamically allocating available network bandwidth. Based on codesign of control and scheduling, an integrated feedback scheduler is developed to enable flexible QoC management in dynamic environments. It encompasses a cascaded feedback scheduling module for sampling period adjustment and a direct feedback scheduling module for priority modification. The inherent characteristics of priority-driven control networks make it feasible to implement the proposed feedback scheduler in real-world systems. Extensive simulations show that the proposed approach leads to significant QoC improvement over the traditional open-loop scheduling scheme under both underloaded and overloaded network conditions.