A CAV Cooperative Lane Change Protocol With CTH Safety Guarantee on Dedicated Highways

Autopiloting <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Connected and Autonomous Vehicles</i> (CAVs) is an important application for mobile computing. A promising context to realize autopiloting CAVs is cooperative driving on dedicated highways. For such a context, an indispensable driving scenario is <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Cooperative Lane Change</i> (CLC). Due to the safety concerns of this driving scenario, a verifiably safe solution is needed (at least, the solution design should be formally provably safe). However, this demand is complicated by the inherently unreliable wireless communications between the CAVs. In this paper, we focus on the well-adopted <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Constant Time Headway</i> (CTH) safety rule. We propose a CLC protocol, and formally prove its guarantee of the CTH safety and liveness, even under arbitrary wireless packet losses. These theoretical claims are further confirmed by our simulations. The simulation results also show that our proposed protocol significantly improves lane change success rates (by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$5.3\% \sim +\infty \%$</tex-math></inline-formula>) than other alternatives under adverse conditions. Furthermore, the sensitivity study results also show our protocol can tolerate reasonable disturbances.