Authors:
Florent Forget
1
;
Kevin Giraud-Esclasse
1
;
Rodolphe Gelin
2
;
Nicolas Mansard
1
and
Olivier Stasse
1
Affiliations:
1
LAAS-CNRS, France
;
2
Softbank Robotics Europe, France
Keyword(s):
Actuation, Humanoids.
Related
Ontology
Subjects/Areas/Topics:
Humanoid Robots
;
Informatics in Control, Automation and Robotics
;
Mechatronics Systems
;
Robot Design, Development and Control
;
Robotics and Automation
Abstract:
Autonomous robots such as legged robots and mobile manipulators imply new challenges in the design and
the control of their actuators. In particular, it is desirable that the actuators are back-drivable, efficient (low
friction) and compact. In this paper, we report the complete implementation of an advanced actuator based
on screw, nut and cable. This actuator has been chosen for the humanoid robot Romeo. A similar model of
the actuator has been used to control the humanoid robot Valkyrie. We expose the design of this actuator and
present its Lagrangian model. The actuator being flexible, we propose a two-layer optimal control solver based
on Differential Dynamical Programming. The actuator design, model identification and control is validated
on a full actuator mounted in a work bench. The results show that this type of actuation is very suitable for
legged robots and is a good candidate to replace strain wave gears.