Optimal coordination of automated vehicles at intersections with turns

In this paper we address the problem of coordinating automated vehicles at intersections, with a special focus on turning maneuvers. The inclusion of rear-end collision avoidance constraints into the problem is decided during turning maneuvers by a smooth function of the vehicle state, rather than integer variables. Moreover, curvature-based acceleration constraints are introduced, which limit the velocity of the vehicle during the turn, and a term in the objective function accounts for passenger comfort. We discuss how the coordination problem is formulated as a nonlinear program and show though simulations that for practical problem instances the proposed approximation is either exact or introduces very little conservativeness.