Comparison of Different Information Display Modes for Smart Glasses Assisted Machine Operations

A pair of commercially available smart glasses, Epson BT-200, was evaluated with different information display modes for assisting machine operators. Two information display modes were selected, displaying animated images only, and displaying animated images with text illustrations. Direction prompts were added in the system. Whether the prompts are helpful or not was also discussed in this study. Task completion time and error rate were collected during the experiment. System Usability Scale (SUS) and NASA-Task Load Index (NASA-TLX) were used to collect subjective information after each experiment. Twenty participants (10 males and 10 females) were recruited. The results showed that the display mode of having smart glasses displaying animated images versus displaying animated images with text illustrations showed no significant difference in task completion time and error rate. But the significant difference was found in the result of SUS scores. Participants preferred the display mode of animate images with text illustrations according to the SUS scores. Moreover, the results indicated that the use of direction prompts had significant influences upon all the measures. Participants completed the tasks faster and had lower error rate by using the smart glasses with direction prompts. And the results of subjective ratings also showed higher SUS score and lower NASA-TLX score were associated with using smart glasses with direction prompts. Thus, the implementation of using smart glasses to guide machine operations should be considered the design of adding direction prompts to increase efficiency and effectiveness of the operations.