A Modeling And Verification Framework For Scenario-based Safety Decision-making In Platoon Systems

To cater for the scenario of coordinated transportation of multiple trucks on the highway,a platoon system for autonomous driving has been extensively explored in the industry.Before such a platoon is deployed,it is necessary to ensure the safety of its driving behavior,whereby each vehicle’s behavior is commanded by the decision-making function whose decision is based on the observed driving scenario.However,there is currently a lack of verification methods to ensure the reliability of the scenario-based decision-making process in the platoon system.In this paper,we focus on the platoon driving scenario,whereby the platoon is composed of intelligent heavy trucks driving on cross-sea highways.We propose a formal modeling and verification approach to provide safety assurance for platoon vehicles’ cooperative driving behavior.The existing Multi-Lane Spatial Logic(MLSL)with a dedicated abstract model can express driving scene spatial properties and prove the safety of multi-lane traffic maneuvers under the single-vehicle perspective.To cater for the platoon system’s multi-vehicle perspective,we modify the existing abstract model and propose a Multi-Agent Spatial Logic(MASL)that extends MLSL by relative orientation and multi-agent observation.We then utilize a timed automata type supporting MASL formulas to model vehicles’ decision controllers for platoon driving.Taking the behavior of a Human-Driven Vehicle(HDV)joining the platoon as a case study,we have implemented the model and verified safety properties on the UPPAAL tool to illustrate the viability of our framework.