Mental Workload and Task Performance for Indirect Vision Driving with Fixed Flat Panel Displays

Of interest to designers of future combat vehicles is the effect of indirect vision upon vehicle driving, and in particular the effect of the camera lens field of view (FOV). In a field study, driving performance was measured for natural and indirect vision with eight participants negotiating a road course in a military vehicle. The indirect vision system was driven with fixed panoramic flat panel, liquid crystal displays in the cab and a forward viewing monocular camera array mounted on the front roof of the vehicle and tilted slightly downward. The results are that the participants successfully drove the vehicle with indirect vision for the different FOVs of the cameras: near unity, wide, and extended. However, they drove the course faster with natural vision than they did with the indirect vision systems. Further, the course speed significantly decreased with increased camera FOV. Workload ratings show a significant increase in perceived workload with increased FOV. Most participants reported a discomfort associated with motion sickness while they were in the moving vehicle with the displays. Finally, cluster analysis of the mental workload measures supports a skills-rules-knowledge model of information processing for the driving task.