On the Safety of Connected Cruise Control: Analysis and Synthesis with Control Barrier Functions

TL;DR

This paper analyzes and synthesizes safe connected cruise control strategies using control barrier functions, ensuring safety measures like minimum distance and time headway while maintaining stability through safety charts.

Contribution

It introduces a formal CBF-based framework for analyzing and designing safety-critical connected cruise controllers, integrating safety measures with stability considerations.

Findings

Formal analysis of safety measures via CBFs

Development of safety charts for controller parameters

Successful numerical verification of theoretical results

Abstract

Connected automated vehicles have shown great potential to improve the efficiency of transportation systems in terms of passenger comfort, fuel economy, stability of driving behavior and mitigation of traffic congestions. Yet, to deploy these vehicles and leverage their benefits, the underlying algorithms must ensure their safe operation. In this paper, we address the safety of connected cruise control strategies for longitudinal car following using control barrier function (CBF) theory. In particular, we consider various safety measures such as minimum distance, time headway and time to conflict, and provide a formal analysis of these measures through the lens of CBFs. Additionally, motivated by how stability charts facilitate stable controller design, we derive safety charts for existing connected cruise controllers to identify safe choices of controller parameters. Finally, we combine the analysis of safety measures and the corresponding stability charts to synthesize safety-critical connected cruise controllers using CBFs. We verify our theoretical results by numerical simulations.