Comparison of open-loop and closed-loop disturbance observers for series elastic actuators

Wesley Roozing; Jörn Malzahn; Darwin G. Caldwell; Nikos G. Tsagarakis

IROS 2016poster33 citations

Comparison of open-loop and closed-loop disturbance observers for series elastic actuators

Wesley Roozing, Jörn Malzahn, Darwin G. Caldwell, Nikos G. Tsagarakis

Abstract

This contribution compares two approaches for applying disturbance observers (DOBs) to the torque control problem of series elastic actuators (SEAs). It is demonstrated that they are in fact equivalent for linear models in terms of their ability to reject disturbances and enforce nominal model dynamics. The closed loop and error transfer functions for the DOB-based approaches are compared to a fully linear plant and a nonlinear plant without DOB. Simulations demonstrate that the DOBs are able to increase the bandwidth of the nonlinear plant significantly, up to that of the linear plant. Furthermore, the DOBs significantly increase the tracking accuracy at low frequencies.

BibTeX

@inproceedings{iros2016_comparisonofopen,
  title = {Comparison of open-loop and closed-loop disturbance observers for series elastic actuators},
  author = {Wesley Roozing and Jörn Malzahn and Darwin G. Caldwell and Nikos G. Tsagarakis},
  booktitle = {IROS 2016},
  year = {2016}
}