Driving in Virtual Reality : Requirements for automotive research and development

Abstract

In the last decades, there has been a substantial increase in the development of complex active safety systems for automotive vehicles. These systems need to be tested for verification and validation to ensure that the system intervenes in the correct situations using the correct measures. There are multiple methods available to perform such testing. Software-in-the-loop and hardware-in-theloop testing offer effective driverless testing. Other methods increase the fidelity by including human drivers, such as driving simulators and experiments performed at test tracks.This thesis examines vehicle-in-the-loop testing, an innovative method where the driver of a real vehicle wears a head-mounted display that displays virtual targets. This method combines the benefits of driving simulators with the benefits of using a real vehicle on a test track. Driving simulators offer repeatability, safety, and the possibility of complex interactions between actors. In contrast, the real vehicle provides the correct vehicle dynamics and motion feedback.There is a need to know how the technology behind the method might influence the results from vehicle-in-the-loop testing. Two techniques for vehicle-in-the-loop systems are studied. The first involves video-see through head-mounted displays, where the focus of the research is on the effects of visual latency on driving behavior. The results show that lateral driving behavior changes with added latency, but longitudinal behavior appears unaffected. The second system uses an opaque head-mounted display in an entirely virtual world. The research shows that this solution changes speed perception and results in a significant degradation in performance of tasks dependent on visual acuity.This research presents results that are relevant to consider when developing vehicle-in-the-loop platforms. The results are also applicable when choosing scenarios for this test method.

Identification of Visual Functional Thresholds for Immersion Assessment in Virtual Reality

“…It represents a degradation of 13.4 degrees from the initial setting of 110 degrees. This functional threshold is smaller than the FOV covered by both eyes when an observer looks straight ahead (Blissing, 2020;Riecke et al, 2006).…”

“…Figure 1 shows a representation of different sections of the FOV. Binocularly, when the eyes are fixed on a point, the human visual system covers a horizontal FOV of approximately 180 to 200 degrees (Perroud et al, 2019b;Blissing, 2020) of which 100 to 120 degrees are covered by both eyes (Wolfe et al, 2006;Blissing, 2020;Riecke et al, 2006), and a vertical FOV of 120 to 140 degrees (Elbamby et al, 2018;Wolfe et al, 2006;Riecke et al, 2006). In head-mounted displays (HMD), it is important to consider the fact that the eyes can move in the presented visual field.…”

“…In comparison, the horizontal FOV of most current generation HMDs is between 90 and 110 degrees. We know that such FOV size makes any task where the observer is detecting objects in peripheral vision difficult to perform (Blissing, 2020). Research that evaluated the FOV size in a virtual environment tends to demonstrate that higher presence is evoked by values closer to the total FOV size (Lin et al, 2002;Slater et al, 2010;Duh et al, 2002).…”

“…Visual performance is not equal across the entire FOV. Increasing eccentricity from the fovea affects motion perception (Blissing, 2020;Lidestam et al, 2019;Hoffman et al, 2018), visual acuity (Ogawa and Shidoji, 2011;Siekawa et al, 2019;Thibos et al, 1996), light and contrast sensitivity (Thibos et al, 1996;Patney et al, 2016), and color perception (Patney et al, 2016;Hoffman et al, 2018;Duchowski et al, 2009;Hansen et al, 2009). These differences in visual qualities performance across the FOV may be responsible for the fact that different functions are attributed to different portions of the visual field.…”

“…This is due to a pixel density too low to reproduce maximal visual acuity (Maxwell et al, 2018). Theoretically, this resolution implies a lack of information that makes objects difficult to discern at distances where they would be clearly identified in real life (Kemeny, 1999;Blissing, 2020). The relation between resolution and perceived realism of a virtual environment is reflected only to some extent in the measure of presence (Felton and Jackson, 2021).…”