Distributed Value of Information in Feedback Control over Multi-hop Networks

Abstract

Recent works in the domain of networked control systems have demonstrated that the joint design of medium access control strategies and control strategies for the closed-loop system is beneficial. However, several metrics introduced so far fail in either appropriately representing the network requirements or in capturing how valuable the data is. In this paper we propose a distributed value of information (dVoI) metric for the joint design of control and schedulers for medium access in a multi-loop system and multi-hop network. We start by providing conditions under certainty equivalent controller is optimal. Then we reformulate the joint control and communication problem as a Bellman-like equation. The corresponding dynamic programming problem is solved in a distributed fashion by the proposed VoI-based scheduling policies for the multi-loop multi-hop networked control system, which outperforms the well-known time-triggered periodic sampling policies. Additionally we show that the dVoI-based scheduling policies are independent of each other, both loop-wise and hop-wise. At last, we illustrate the results with a numerical example.

Control-aware scheduling over multi-hop networks

“…The authors of [27] jointly design policies for sampling, scheduling, and control for multi-hop WNCSs that minimizes control cost but it considers negligible communication delays and no packet losses. The work [28] considered scheduling over multi-hop that is optimized w.r.t. control cost, but there are constant delays and no losses from the network side.…”