Evaluation of a Visual–Tactile Multimodal Display for Surface Obstacle Avoidance During Walking

The future of human space exploration will involve extra-vehicular activities (EVAs) on foreign planetary surfaces (i.e., Mars), an activity that will have significantly different characteristics than exploration scenarios on Earth. These activities become challenging due to restricted vision and limitations placed on sensory feedback from altered gravity and the space suit. The use of a bulky, pressurized EVA suit perceptually disconnects human explorers from the hostile environment, increasing navigation workload and the risk of collision associated with traversing through unfamiliar terrain. Multimodal displays are considered as a means to provide information to the astronaut as cues to multiple sensory modalities enhance cognitive processing through taking advantage of multiple sensory resources, and are believed to communicate the risk more efficiently than unimodal cues. This paper presents a wearable multimodal interface system to examine human performance when visual, vibratory, and visual–vibratory cues are provided to aid in ground obstacle avoidance. The wearable system applies vibrotactile cues to the feet and visual cues through augmented reality glasses to convey obstacle location and proximity. Participants ( n  = 16) performed an overground obstacle avoidance task with the multimodal device. Performance metrics included completion time, subjective workload, head-down time, collisions, as well as gait parameters. Results indicate that information displays enhance task performance, with the visual-only display promoting the least head-down time over tactile-only or visual–tactile displays. Head-down time was the highest for trials without a display. Results provide implications for presenting information during physically active tasks such as suited obstacle avoidance.