Preliminary Study of Tactical-Level Interaction for Highly-Automated Vehicles: Its Application to Touchscreen Interface

In automated vehicles, drivers are only required to input high-level control commands. The conventional driver-vehicle interfaces (DVIs) such as steering wheel and pedals that function in operational level may not be utilized in higher levels of automation. A DVI that allows the driver to input tactical-level control commands, .e.g., lane change, by easily understanding a situation, would be potentially required for automated vehicles. We thus propose tactical-level-interaction (TLI) for lateral and longitudinal controlling of highly automated vehicles. In this study, we developed a touchscreen-based DVI that allows the driver to use touch gestures to input tactical control commands. The screen displays an augmented map including the ego vehicle rendered from the top view. The driver can instantly input a set of lateral commands by location-based TLI, e.g., lane changing, by designating a desired location on the map, e.g., lane, by double tapping and swiping. We performed experiments using a simulator to evaluate TLI compared with the operational- (OLI) and strategical-level interaction (SLI). The results show that TLI offers both the flexibility of OLI as well as comfort of SLI, and drivers prefer to use all three interaction methods depending on the driving environment.