Formal Verification of a Map Merging Protocol in the Multi-Agent Programming Contest

Abstract

Communication is a critical part of enabling multi-agent systems to cooperate. This means that applying formal methods to protocols governing communication within multi-agent systems provides useful confidence in its reliability. In this paper, we describe the formal verification of a complex communication protocol that coordinates agents merging maps of their environment. The protocol was used by the LFC team in the 2019 edition of the Multi-Agent Programming Contest (MAPC). Our specification of the protocol is written in Communicating Sequential Processes (CSP), which is a well-suited approach to specifying agent communication protocols due to its focus on concurrent communicating systems. We validate the specification's behaviour using scenarios where the correct behaviour is known, and verify that eventually all the maps have merged.

MLFC: From 10 to 50 Planners in the Multi-Agent Programming Contest

“…We have formally verified the protocol we made to merge map information [15]. Other than this we did not invest much time apart from the last few days before the contest when we tried to make the team more fault-tolerant towards task failures.…”

“…FDR also includes the Probe tool, which allows the user to step through the available events in the specification. We summarise how we used FDR to formally verify the map merge protocol in Section 4.2, and a full description can be found in [15].…”

“…As mentioned in Section 2, we specified the map merging protocol in the formal language CSP and used the model checker FDR for both validation and verification, as described below. A complete description of the specification and verification effort is presented in [15].…”