Connection between Quantisation and Bandwidth Requirements of Distributed Model Predictive Control

Many distributed systems rely on communication as a necessary condition to steer the overall system to a reference or target state, which may lead to a large bandwidth requirements. Here, we consider a Distributed Model Predictive Control Scheme (DMPC) where each agent predicts its own trajectory in every time step, which is then broadcasted among the agents. We aim to reduce the necessary communication and introduce the concept of prediction coherence as a degree of difference of two predictions in two successive time steps. We evaluate the influence of quantisation of communicated predicted states on the prediction coherence in a street traffic model for a quantised intersection in order to incorporate possible disturbances in communication. We numerically observe that prediction coherence reveals a bound for the minimal bandwidth requirements for such a distributed control setting. (C) 2017, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.