Adapting Time Headway in Cooperative Adaptive Cruise Control to Network Reliability

Wireless network impairment results in adverse effect on string stability of a Cooperative Adaptive Cruise Control (CACC) platoon that relies on the wireless network, causing disturbances in the platoon that may lead to a collision. Previous work in the literature proposed fallback strategies that utilizes on-board sensors to recover in case of wireless network impairment, those methods assumes a fixed time headway value. In this paper, we study the string stability of a one-vehicle look-ahead CACC platoon under different network loss scenarios, and propose to adapt the time headway parameter of the model according to a network reliability metric that we defined based on packet burst loss length to maximize traffic flow efficiency while maintaining a string-stable platoon. Our findings show that careful adjustment of headway value according to the wireless network reliability allows the platoon to maintain string-stable operation while maximizing traffic flow.