The virtual penetrating the physical and the implication for augmented reality head-up displays

Abstract

Augmented Reality is one of the upcoming topics in the development of human machine interfaces (HMI). The most promising technology using Augmented Reality to assist the user in his driving task is the Augmented Reality Head-Up Display (ARHUD). By reflecting virtual information at the windscreen into the driver’s eyes, the impression of a hovering image is created. The virtual image can be overlaid on the road surface or penetrate into an object in which case an observer has to focus upon a distance further away than – or through – the object he is looking at. So far, the industry wide opinion on how to handle this has been either to change the HMI or to switch off the augmentation. Though it has not yet been investigated whether this influences spatial perception, usability or acceptance of the ARHUD [1]. In the current study we investigated whether penetration of the virtual image with a fixed image distance of 10 m into a leading vehicle was perceived as disturbing or influenced usability or cognitive workload. Navigation arrows were displayed in a fixed distance of 12 m using only monocular depth cues and superimposed by a vehicle in 6.6 m (low penetration) and 3.8 m (high penetration) distance. As a baseline, the leading vehicle was positioned at 13.8 m distance and thereby not superimposing the virtual image (no penetration). On both sides of the leading vehicle assistants presented visual cues which the subject was asked to count. Additionally subjects performed a visual Detection Response Task to evaluate the subjects’ reaction times and cognitive workload [2]. Usability was evaluated using the System Usability Scale [3]. High penetration led to a significant change in acceptance when compared to no penetration. Usability, number of errors and reaction times were not significantly influenced. For low penetration no significant effects were recorded. The results suggest that adapting the virtual information displayed in an ARHUD in order to mediate penetrations between the virtual image and physical objects is not necessary. This has the potential to revolutionize the approach the automotive industry takes when implementing Augmented Reality in Head-Up Displays.