Byzantine fault tolerance for centrally coordinated missions with unmanned vehicles

Abstract

Autonomous unmanned vehicles can support a wide range of missions, which are typically coordinated by a human operator. Automating these missions through a computer program can offer great advantages, but at the same time introduces several challenges. In particular, it becomes important to tolerate failures of the mission controller, including the most general type, namely Byzantine failures. To address this challenge, we propose an active replication approach adapted to the characteristics of this particular type of system. Our solution relies on signed messages and requires N = 2 × f + 1 mission controller replicas to tolerate f Byzantine failures. We describe the system model and the mechanisms that need to be in place to achieve the desired functionality, and argue about the correctness of the proposed approach in an informal way. Also, we evaluate the overheads of a prototype implementation through indicative simulation experiments.