Information integration and instruction authoring of augmented assembly systems

Augmented assembly (AA) is being gradually incorporated into manual assembly owing to its abundant instruction forms, high efficiency of information transmission, and robust interactivity. However, a lack of a unified description model for assembly information and irregular instruction design forms leads to difficulties in instruction authoring and generation, inconveniences for data management, and low system portability. To address these issues, this paper presents an information-integration and instruction-authoring method for AA systems. First, design guidelines for the AA instructions are established with the aim of minimizing the user's cognitive load. After that, the designing of visual elements is performed based on the design guidelines, and the information model of the assembly information and instructions is built using Unified Modeling Language. Based on Extensible Markup Language files and Unity3D engine, a standard and rapid development process is presented for deploying the AA system to Hololens2 devices. The usability and replicability of the designed system are demonstrated, and a user study is carried out. The user's task performance is evaluated using completion time and errors as metrics. The NASA-task load index scale is used to estimate the user's workload, and the Likert scale reflects the user's subjective perception of the system and instructions. The results show that the proposed AA instructions can effectively improve the user's task performance; reduce their workload, especially the cognitive load; and improve their assembly experience.