Technology to create a digital twin of an actual robot using external sensors built with ETR Lab’s own technology.

We verified the main inverse kinematics (IK) solutions using MuJoCo simulation and evaluated the agreement with the actual robot. After obtaining the IK solution based on the DH (Denavit-Hartenberg) parameters of the robot, the path generated by MuJoCo was identically reproduced on the actual robot, and the robot’s pose was measured using an infrared position tracker.

The trajectory was generated by interpolating the passing points during pose transitions between various standard poses (vertical upright, horizontal full stretch, 90-degree bending of the upper arm and forearm, etc.). The distance difference between the MuJoCo trajectory and the actual robot trajectory was analyzed, and the error rate was quantitatively evaluated.

The analysis shows that the IK solver used in this study has high accuracy and can be applied to various robot systems assuming no linear motion joints are included.