A Functional Co-Design towards Safe and Secure Vehicle Platooning

Cooperative adaptive cruise control (CACC) or platooning recently becomes promising as vehicles can learn of nearby vehicles? intentions and dynamics through wireless vehicle to vehicle (V2V) communication and advanced on-board sensing technologies. Violation of cybersecurity often results in serious safety issues as been demonstrated in recent studies. However, safety and security in a vehicle platoon so far have been considered separately by different sets of experts. Consequently no existing solution solves both safety and security in a coherent way. In this paper, we show cyber attacks on an automated platoon system could have the most severe level of safety impact with large scale car crash and argue the importance of safety-security co-design for safety critical cyber physical systems (CPS). We propose a safety-security co-design engineering process to derive functional security requirements for a safe automated vehicle platoon system based on a deep comprehension on the interrelation of safety and security. To our best knowledge, we are the first to apply the safety-security co-design concept to a concrete application. Through this engineering process, we propose a general approach for designing a safe and secure platooning. Following the general approach, we come up with a new platoon control algorithm that takes into account both safety and security. Our defense mechanism implicitly defends against safety-related cyber-attacks and greatly shortens the safe distance required when the platoon is not protected.