Exploring Real-time Precision Feedback for AR-assisted Manual Adjustment in Mechanical Assembly

Augmented Reality (AR) based manual assembly nowadays enables to guide the process of physical tasks, providing intuitive instructions and detailed information in real-time. However, very limited studies have explored AR manual adjustment tasks with precision requirements. In this paper, we develop an AR-assisted guidance system for manual adjustments with relatively high-precision requirements. We first assessed the accuracy of the special-set OptiTrack system to determine the threshold of precision requirements for our user study. We further evaluated the performance of Number-based and Bar-based precision feedback by comparing orienting assembly errors and task completion time, as well as the usability in the user study. We found that the assembly errors of orientation in the Number-based and Bar-based interfaces were significantly lower than the baseline condition, while there was no significant difference between the Number-based and Bar-based interfaces. Furthermore, the Number-based showed faster task completion time, lower workload, and higher usability than the Bar-based condition.