A visuo-haptic mixed reality manual milling training simulator

With the advancements in technology, mixed reality (MR) has found numerous applications in industries and job training. However, most MR applications only provide visual feedback, lacking realistic haptic feedback. Nevertheless, certain jobs require haptic sensations in the hands. To address this issue, this study integrates realistic haptic feedback into an MR environment and develops a visuo-haptic MR milling simulator for conventional manual milling operation training using Microsoft HoloLens 2. This simulator comprises a virtual spindle, a virtual milling tool, a virtual workpiece, and a physical mockup of the milling table. It provides realistic cutting force feedback when the virtual milling tool collides with the virtual workpiece. Users can operate the milling simulator with their bare hands and feel cutting force as if they were operating a real milling machine. The developed training system allows novices to intuitively understand the relationship between milling parameters and milling conditions. The usability and immersiveness of the visuo-haptic MR milling simulator are studied, and the results show that realistic haptic feedback increases usability, realism, immersiveness, and presence.