Closed-Loop Robotic Arm Manipulation Based on Mixed Reality

Abstract

Robotic manipulators have become part of manufacturing systems in recent decades. However, in the realm of Industry 4.0, a new type of manufacturing cell has been introduced—the so-called collaborative manufacturing cell. In such collaborative environments, communication between a human operator and robotic manipulators must be flawless, so that smooth collaboration, i.e., human safety, is ensured constantly. Therefore, engineers have focused on the development of suitable human–robot interfaces (HRI) in order to tackle this issue. This research work proposes a closed-loop framework for the human–robot interface based on the utilization of digital technologies, such as Mixed Reality (MR). Concretely, the framework can be realized as a methodology for the remote and safe manipulation of the robotic arm in near real-time, while, simultaneously, safety zones are displayed in the field of view of the shop-floor technician. The method is based on the creation of a Digital Twin of the robotic arm and the setup of a suitable communication framework for continuous and seamless communication between the user interface, the physical robot, and the Digital Twin. The development of the method is based on the utilization of a ROS (Robot Operating System) for the modelling of the Digital Twin, a Cloud database for data handling, and Mixed Reality (MR) for the Human–Machine Interface (HMI). The developed MR application is tested in a laboratory-based machine shop, incorporating collaborative cells.