Semi-autonomous control of multiple heterogeneous vehicles for intersection collision avoidance

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.Includes bibliographical references (pages 79-80).This paper describes the design of a supervisory controller (supervisor) that manages multiple heterogeneous vehicles, i.e., multiple controlled and uncontrolled vehicles, to avoid intersection collisions. Two main problems are addressed: verification of the safety of all vehicles at an intersection, and management of the inputs of controlled vehicles. For the verification problem, we employ an inserted idle-time scheduling approach, where the "inserted idle-time" is a time interval when the intersection is deliberately held idle for uncontrolled vehicles to safely cross the intersection. For the management problem, we design a supervisor that is least restrictive in the sense that it overrides controlled vehicles only when a safety violation becomes imminent. We analyze computational complexity and propose an efficient version of the supervisor with a quantified approximation bound. To mitigate the abrupt changes of control inputs and to reduce the number of unnecessary interventions, we additionally design two optimization problems and provide the supervisor with a more conservative bound.by Heejin Ahn.S.M