Facilitating Robot Kinematics Learning through Mixed Reality: Development of an Interactive Application

With the growing interest in robotics within STEM, robot kinematics has become a pivotal area of study. Denavit–Hartenberg parameters (D-H parameters), which is an approach to perform robot kinematics, have thus been widely explored by students. This approach involves assigning coordinate frames to robot joints based on a set of rules and determining four parameters between every two neighboring frames, which demands strong 3D spatial reasoning. However, due to the lack of a direct 3D visualization approach, it poses great challenges for learners. To address this, we proposed a mixed reality application for HoloLens 2 that incorporates both training and testing sessions to enhance 3D visualization of the D-H parameters. The training session offers virtual coordinate frames overlaid on a physical robot, synchronizing their movements with the joints by tracking the motion of the robot links via a set of fiducial markers. During the testing session, users interact with diagrams displaying various robots to evaluate their understanding of the D-H parameters. A quantitative evaluation was conducted to assess the technology of the application, focusing on how well the coordinate frames are placed on the Fanuc LR Mate 200iD robot. While there are deviations between the generated frames and the ground truth, these are either within acceptable limits or barely noticeable. This demonstrated the feasibility of the technology and highlighted the significant potential of applied AR technology in enhancing robotics education within STEM.