Exploring Users' Eye Movements when Using Projection-Based Assembly Assistive Systems

Projection-based assistive systems have shown to be a promising technology to support workers during manual assembly processes in industrial manufacturing by projecting instructions into the working area. While existing studies have investigated various aspects of these systems, little research has been conducted regarding the way in which the user accesses the provided instructions. In this paper we analyze the eye movements of users during the repeated execution of an assembly task at a projection-based assistive system in order to gain insights into the utilization of the presented instructions. For this purpose, we analyzed eye tracking recordings from a user study with 15 participants to investigate the sequences in which the respective instructions are observed by the users. The results show a significantly lower number of nonlinear gaze sequences as well as a significantly higher number of steps without observing the instructions during the repeated use of the assistive system. In addition, there was a significantly lower task completion time during repeated use of the assistive system.