A cascade steering shared controller with dual-level dynamic authority

Advanced Driver Assistance Systems (ADAS) that consider the driver in the control loop (Shared Control ADAS) have the potential to influence upcoming functionalities in partially automated vehicles, improving the driving performance, reducing the workload, and increasing safety. According to the literature, two design parameters are relevant based on the cognitive level of the driving task. First, at the operational level, the steering controller must have a variable Level of Haptic Authority (LoHA), demanding more or less effort from the driver to override the system. Secondly, the tactical level needs an arbitration system to manage the transitions from manual-to-automated and automated-to-manual safely and progressively, with a variable Level of Shared Authority (LoSA). Based on these premises, this paper presents a cascade steering shared controller with a dual-level authority. The operational level consists of a hybrid MPC-PD controller, and the tactical level uses a Fuzzy Inference System (FIS). Results show the benefits of the system, assisting the driver in a collaborative overtaking maneuver.