System-Level Modeling and Safety Analysis of Vehicular Coordinated Emergency Braking Under Degraded Wireless Connectivity Using Priced Timed Automata

摘要

The technological advances in automated driving systems have led to the development of autonomous vehicles. As more of these vehicles go out in the streets, new opportunities arise to achieve various types of benefits by applying coordination among vehicles. For these coordinated systems to be approved for street deployments, they have to prove safety under realistic scenarios that involve parameter uncertainties and temporal faults. In this paper, new modeling and formal analysis of vehicular coordinated emergency braking system are proposed using priced timed automata. The modeling captured the behavior of the underlying physical systems, coordination protocol, wireless connectivity, and the scenario uncertainties. The analysis framework is used to identify conditions required for safe emergency braking with statistical guarantees. The analysis investigated the safety of a coordinated emergency braking protocol under an error-free scenario and under a scenario that involves degraded wireless connectivity. A retransmission scheme is also analyzed which resulted in safety improvement.