In-Situ Instructions Exceed Side-by-Side Instructions in Augmented Reality Assisted Assembly

Driven by endeavors towards Industry 4.0, there is increasing interest in augmented reality (AR) as an approach for assistance in areas like picking, assembly and maintenance. In this work our focus is on AR-based assistance in manual assembly. The design space for AR instructions in this context includes, e.g., side-by-side, 3D or projected 2D presentations. In previous research, the low quality of the AR devices available at the respective time had a significant impact on performance evaluations. Today, a proper and up-to-date comparison of different presentation approaches is missing. This paper presents an improved 3D in-situ instruction and compares it to previously presented techniques. All instructions are implemented on up-to-date AR hardware, namely the Microsoft HoloLens. To support reproducible research, the comparison is made using a standardized benchmark scenario. The results show, contrary to previous research, that in-situ instructions on state-of-the-art AR glasses outperform side-by-side instructions in terms of errors made, task completion time, and perceived task load.