A Quantitative Comparison of Operator Field of View for Vehicle Design
King, M. D., Jinkerson, J. L., Garrison, T. M., Irby, D., & Carruth, D. W. (2016). A Quantitative Comparison of Operator Field of View for Vehicle Design. AHFE 2016. Orlando, FL.
A key aspect of task performance when operating a vehicle is the ability of the occupant to sense relevant visual information in the driving environment. Current tools for evaluating field of view assess where operators are likely to look and where they are able to see, rather than quantitatively defining what operators can see. We sought to define quantitative metrics for calculating the visibility of task-specific visual information given the occlusion of an occupant’s field of view by vehicle geometry. This paper describes a preliminary application of a method to evaluate the ability of an operator of three consumer vehicles to observe task-specific visual information. To address the need for quantitative methods of categorizing and calculating the occurrence of task-specific visual information, we combine maps of categorical visual information with occlusion maps based on spherical projections.
We generated quantitative representations of the relative frequency of the appearance in the total available field of view of task-specific classifications of visual information (e.g., buildings, roadway surfaces, navigation signs) from static imagery of randomly selected locations in the continental United States. This visual information represents where and how often task-relevant visual information is likely to appear in the driving environment. The second step in our calculation of effective field of view employed software to calculate occlusion maps of virtual models of existing or concept vehicles. Occlusion maps represent the area of the occupant’s total field of view that is occluded by vehicle geometry. Occlusion maps were overlaid by the visual information maps to calculate vehicle and environment-specific statistics, resulting in a quantitative, comparable representation of the occupant’s effective field of view.
For this project, we created occlusion maps for three consumer vehicles: a compact pickup truck, a full-size pickup truck, and a midsize sedan. For each vehicle, we calculated occlusion maps for occupant eye points corresponding to that of a 5th percentile female, a 50th percentile female, a 50th percentile male, and a 95th percentile male. We evaluated the combined effects of driving environment, vehicle geometry and occupant eye height on driver ability to observe visual information critical to the task of driving: roadway surfaces, roadside vehicles, and navigation signs. We compare the results for the three vehicles and demonstrate the additional diagnostic information provided by our analysis. This analysis provides researchers and designers with the ability to quantitatively assess and compare the task-relevant effective field of view for vehicle occupants by calculating the combined influences of operator task, vehicle design, driving environment, and anthropometry. In sum, the preliminary results indicate that we have a quantitative method for assessing what visual information vehicle operators and occupants can see.