Benefits of V2V Communication for Autonomous and Connected Vehicles

TL;DR

This paper analyzes how Vehicle-to-Vehicle communication enhances the stability and reduces the minimum employable time headway in autonomous vehicle platoons, especially considering parasitic actuation lags.

Contribution

It quantifies the reduction in minimum employable time headway achievable through V2V communication using different sets of predecessor vehicle information.

Findings

Using position and velocity of r vehicles reduces h_min to 4τ₀/(1+r).

Including acceleration data further reduces h_min to 2τ₀/(1+r).

Using position, velocity, and acceleration of immediate and r-th predecessors yields the same lower bound as (2) but with less communication.

Abstract

In this paper, we investigate the benefits of Vehicle-to-Vehicle (V2V) communication for autonomous vehicles and provide results on how V2V information helps reduce employable time headway in the presence of parasitic lags. For a string of vehicles adopting a Constant Time Headway Policy (CTHP) and availing the on-board information of predecessor's vehicle position and velocity, the minimum employable time headway ($h_{\min}$) must be lower bounded by $2\tau_0$ for string stability, where $\tau_0$ is the maximum parasitic actuation lag. In this paper, we quantify the benefits of using V2V communication in terms of a reduction in the employable time headway: (1) If the position and velocity information of $r$ immediately preceding vehicles is used, then $h_{\min}$ can be reduced to ${4\tau_0}/{(1+r)}$; (2) furthermore, if the acceleration of `$r$' immediately preceding vehicles is used, then $h_{\min}$ can be reduced to ${2\tau_0}/{(1+r)}$; and (3) if the position, velocity and acceleration of the immediate and the $r$-th predecessors are used, then $h_{\min} \ge {2\tau_0}/{(1+r)}$. Note that cases (2) and (3) provide the same lower bound on the minimum employable time headway; however, case (3) requires much less communicated information.