A Study of the Effects of Lens Focal Length on Remote Driver Performance

Abstract : The effects of three lens focal lengths on remote driving performance were measured. The three focal lengths and their corresponding horizontal fields of view (FOVs) were 12 mm (29 deg), 6 mm (55 deg), and 3.5 mm (94 deg). On-board driving performance (direct view) was also measured. The study was conducted on an indoor test course consisting of six segments: straightaways, right-hand turns, left-hand turns, serpentine, figure 8, and obstacle avoidance. The findings indicate that for the first five segments of the course, driving speed and accuracy were significantly greater (p <.05) with the 6-mm lens than with either the 12-mm or the 3.5-mm lens. In the last course segment (obstacle avoidance), speed and accuracy were significantly less (p <.05) with the 12-mm lens than with either the 6-mm or the 3.5-mm lens. Differences between the latter two lenses in speed and accuracy were not statistically significant. For the first five segments of the course, significantly greater speed and accuracy (p <.05) was achieved during on-board operations than during operations in the remote mode using the 6-mm lens. In the obstacle avoidance segment, speed was also significantly greater in the on-board mode (p <.05), but there was no significant difference in speed between the 6-mm and the 3.5-mm lens. In this analysis, the 6-mm lens was found to be less accurate (p <.05) than the 3.5-mm lens or the on-board driving mode, but the significance of this difference was considered marginal. No significant difference in accuracy was found between on- board driving and remote operations using the 3.5-mm lens. .... Field of view, Remote control, Teleoperation, Focal length, Remote driving, Unmanned ground vehicle, Indirect vision, Robotics.