Modeling Indirect Vision Driving With Fixed Flat Panel Displays: Task Performance and Mental Workload

The relation between mental workload and situational awareness and the effects on vehicle performance are of interest to designers of future combat ground vehicles. In this report, a micro-state task time line analysis of attention workload is used to describe a model of driving performance and mental workload for indirect vision driving. The model is based on the results of a field study in which a military vehicle was driven with flat panel, liquid crystal displays fixed in the cab and a forward viewing monocular camera array mounted on the front roof. The task load times for the model are calculated with a mathematical equation for vehicle speed as a function of the camera field of view. The vehicle speed equation is derived with consideration given to the effects of scene compression on the informational needs of the driver in a self-paced task. An analysis shows that the task performance and mental workload are separable for the short course runs used in the field study. The effect of indirect vision driving on mental workload is determined from the subjective ratings of perceived task loading that were reported in the field study. Along with the perceived workload, the study participants rated the mental measures of task allocated attention, situational awareness, motion sickness, and subjective stress. Because of collinearity, the perceived workload is regressed on the factorial components of a cognitive loading space derived from a factorial analysis of the mental measures. Following rotation to a 'skills-rules-knowledge' cognitive processing space derived from the clustering of the measures, the perceived workload is shown to be a function of the skills and rule-based components. On this basis, a micro-state time line model is proposed for the task information processing. --Original contains color plates: All DTIC reproductions will be in black and white.