Otimização do consumo energético em sistemas de controle sem fio através de controle preditivo e redundância incremental

Abstract

Wireless networked control systems are an integral part of the new usage scenarios considered for the fifth generation of mobile networks (5G) which, in addition to surpassing previous generations in data rate and capacity, aim to address them. They are present in applications such as V2X communication and Industry 4.0, for example, using realtime control, which implies strict latency and reliability requirements for communication. In this type of system, the most common form of communication between devices occurs through short packages, requiring specific mathematical models for an appropriate project. Additionally, control and communication cannot be considered individually, as there are variables that influence both concurrently. The co-design benefits for meeting the URLLC (Ultra-Reliable Low Latency Communication) requirements have already been demonstrated by improving resource utilization while increasing information traffic through the use of PPC (Packetized Predictive Control). This is an extremely important factor, considering that in the context of wireless systems, it is common for the elements to be powered by batteries. The consumption is further reduced when HARQ (Hybrid Automatic Repeat reQuest) is applied, and a retransmission of the message is provided in case of an outage event. In this work, both techniques are applied, whereas supporting short packets communication, to obtain an optimum number of retransmissions and predictive control commands, aiming for better energy efficiency. The results show that by performing an appropriate choice of these parameters, it is possible to optimize consumption. Also, depending on the latency restrictions of the system, the use of PPC may not be interesting, being HARQ alone a better alternative.