Analysis of a wearable, multi-modal information presentation device for obstacle avoidance

The future of human space exploration will involve extra-vehicular activities (EVA) on foreign planetary surfaces (i.e. Mars), an activity that will have significantly different characteristics than the common exploration scenarios on Earth. These activities become challenging due to restricted visual cues and other limitations placed on sensory feedback from altered gravity and the pressurized suit. The use of a bulky, pressurized EVA suit perceptually disconnects human explorers from the hostile foreign environment, increasing the navigation workload and risk of collision associated with traversing through unfamiliar terrain. Due to the hazardous nature of this work, there is a critical need to design multimodal interfaces for optimizing task performance and minimizing risks; in particular, an information presentation device that can aid in obstacle avoidance during surface exploration and way-finding. Previous research has shown that multimodal cues can communicate risk more efficiently than cues to a single modality. This paper presents a wearable interface system to examine human performance when visual, vibratory, and visual-vibratory cues are provided to aid ground obstacle avoidance. The wearable system applies vibro-tactile cues to the feet and visual cues through augmented reality glasses to convey obstacle location and proximity during an approach. This study examined participants stepping over a randomly placed obstacle in a path while wearing the multimodal interface. Measures of performance included path completion time, subjective workload, head-down time, collisions, as well as gait parameters. Differences in obstacle avoidance performance were analyzed across conditions and results provide implications for presenting multimodal information during active tasks such as obstacle avoidance.