Robust force control with a novel gain tuning methodology based on the stable margin theory

This paper proposes a force control system using the State Observer Based Disturbance Observer (SO-DOB) and the State Observer Based Reaction Force Observer (SO-RFOB) based on the novel observer gain tuning methodology. The observer gain tuning methodology is based on the stable margin theory. By using the proposed gain tuning methodology, the system stability and the robustness of the SO-DOB and the SO-RFOB is guaranteed. The validity of the proposed method was tested by both simulation and the experiment works. From the results, the control performance was improved compared with the DOB and the RFOB based on the Low Pass Filter (LPF) based estimation.