Decentralized Time and Energy-Optimal Control of Connected and Automated Vehicles in a Roundabout

We consider the problem of controlling Connected and Automated Vehicles (CAVs) traveling through a three-entry roundabout so as to jointly minimize the travel time and energy consumption while providing speed-dependent safety guarantees and satisfying velocity and acceleration constraints. We first design a systematic approach to dynamically determine all conflicting CAVs defining the safety constraints under different CAV sequencing policies. A joint optimal control and barrier function (OCBF) method is then applied to efficiently obtain a controller that optimally tracks the unconstrained optimal control solution while guaranteeing the satisfaction of all constraints. Simulation experiments performed to compare the OCBF controller to a baseline of human-driven vehicles show its effectiveness under different roundabout configurations and sequencing policies.