A Fault-Tolerant Controller Manager for Platooning Simulation
Recent development in wireless technology enabling communication between vehicles led to introduction of the concept of Cooperative Adaptive Cruise Control (CACC), which uses wireless vehicle-to-vehicle communication and aims at string stable behavior in a platoon of vehicles. Degradation cascades have been proposed as a way to maintain a certain level of the system functionality in presence of failures. Such degradation behaviour is usually controlled by a runtime/state manager that performs fault detection and transitions the system into states where it will remain acceptably safe. In this paper, we propose a dynamic controller manager that focuses on both safety and performance of the system. In particular, it monitors the channel quality within the platoon and reacts by degrading platoon performance in presence of communication failures, or upgrading the performance when the communication quality is high enough. The reaction can include, e.g., adjusting the inter-vehicle distance or switching to another suitable platoon controller to prevent collisions. We focus on the functional and operational safety and evaluate the performance of the dynamic controller manager under different scenarios and settings in simulation experiments to demonstrate that it can avoid rear-end collisions in a platoon, continue platooning operation even in dense traffic scenarios where the state-of-the-art controllers fail to do so.