Modeling the Orientation of Take-Over Trajectories Using Mixed Linear Effects Models

As automation of driving emerges, the driver becomes a passenger. If an automation reaches its system limits, the driver is obliged to retake the control over the vehicle. Grabbing the steering wheel is essential to assume lateral control, however non-driving related activities enabled by the automation may interfere with this process. This paper showcases the method modeling the orientation of hand trajectories while grabbing four different handles. In a study presented in [1] the hand trajectories of 48 participants grabbing four different handles were recorded and modelled using a mixed linear effects approach. The present paper extends this research by modeling the orientation of these trajectories. As the grasping trajectories appear to lie on a two-dimensional plane, the angle between the trajectory plane and a reference plane was modeled in a mixed linear effects model with “lme4” [2] and “afex” [3]. The maximal deviation from the plane is 10.7 mm with a mean of 2.3 mm (SD = 1.3 mm). The data shows the small influence of individual (gender, age, dominant hand, body height) and the high influence of environmental (position and type of the grasping handles) factors.