A Two-Stage Suboptimal Approximation for Variable Compliance and Torque Control

  • Posted on: 9 February 2015
  • By: ostasse
TitleA Two-Stage Suboptimal Approximation for Variable Compliance and Torque Control
Publication TypeConference Paper
Year of Publication2014
AuthorsGeoffroy, P, Bordron, O, Mansard, N, Stasse, O, Raison, M, Bretl, T
Conference NameEuropean Conference on Control
Abstract

Variable-stiffness actuator is a very appealing mechatronic design that combines the efficiency of stiff actuator  in free space with the consistency of elastic actuation in contact. The control of such an actuation system remains a challenge due to its non-linearity and by the fact that it doubles the number of control inputs. In this paper, we propose an original
control strategy to compute the whole-body movement of a complex variable-stiffness robot during dynamic task execution. Operational space control is first used to compute both the joint torque and stiffness from operational references. A nonlinear model-predictive controller is then proposed to track at higher frequency these references on each joint separately. The effectiveness of this approach is then validated on two models of real actuator with adjustable stiffness, and finally on an explosive motion to make a humanoid robot jump.

URLhttps://hal.archives-ouvertes.fr/hal-01114610/document
DOI10.1109/ECC.2014.6862557
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