摘要
Augmented Reality (AR) technology has increasingly been applied to facilitate manufacturing tasks such as training, maintenance, and safety management, in which manual assembly frequently occurs. Previously, studies confirmed the values of AR-based assembly systems, but few explored support of spatially restricted assembly where components are visually occluded from operator. In this regard, this research aims to develop new AR functions that assist manual assembly in such situations. The focus is on validating the effectiveness of various assistive information in AR, including assembly interface, operator's hand movement, and operator held components. Subjective and objective measures are used to evaluate assembly experiments of different degrees of difficulty. Analyses of the experimental data reveal whether or not and how effectively each information offers guidance in occluded condition. In particular, a time reduction in more difficult assembly is realized by showing operator hand movement in AR. The hand model initially offers an operator a visual clue for quickly and roughly locating the assembly interface in a large unseen area, prior to precisely localizing in a smaller region guided by tactile sensing. However, the effectiveness of incorporating the held component is not evident, as positional deviation between real and virtual objects may reduce human's hand-eye coordination. These findings not only provide preliminary design guidelines of AR assembly functions for occluded components but also demonstrates a novel yet practical application of AR technology in smart manufacturing.