Analysis of Estimation Performance of Load-side Torque and Load-side Velocity Observers for Human Interaction Control Based on Torsion Torque Control

This paper proposes a back-forward drivable control based on torsion torque control (TTC) that achieves both back-forward drivability and vibration suppression for a two-inertia system. The proposed system combines the TTC that consists of I-P controller and velocity deviation feedback and a motor-side normalization compensator (MNC) to facilitate human-robot interactions. For the velocity deviation estimation, load-side torque observer (LTOB) and load-side velocity observer (LVOB) are evaluated on estimation performance. The better observer is applied to the TTC from the analysis results. The effectiveness of the proposed control system is verified by simulation and experimental results, and the vibration of the back-forward drivable response is considerably suppressed.