Authors:
T. Watanabe
;
D. Kamo
;
D. Tanaka
;
T. Nakamura
and
H. Osumi
Affiliation:
Chuo University, Japan
Keyword(s):
Artificial Muscle, Differential Gear, Disturbance Observer, Nominal Model.
Related
Ontology
Subjects/Areas/Topics:
Informatics in Control, Automation and Robotics
;
Mechatronics Systems
;
Robot Design, Development and Control
;
Robotics and Automation
Abstract:
Recently, the demand for robots that operate in the fields of nursing and human life have increased due to the aging population and falling birthrates. Since these robots are intended to operate near humans, it is necessary they should have increased safety measures. Moreover, since it is desired that these robots use actuators that are light and soft, in several cases artificial muscles have been used as actuators. However, the Mckibben-type artificial muscles that are most commonly used have several drawbacks. Therefore, we developed a straight-fiber-type artificial muscle that was utilized to construct a two degree-of-freedom (2-DOF) manipulator. Because the manipulator is equipped with a differential gear mechanism, it is capable of performing 2-DOF bending and torsion motions using only one mechanism. However, the rotation speed of gears respectively differs in this mechanism, so the interference occurs in unintended directions because the speed of contraction and extension of t
he artificial muscle respectively differs. To address this problem, we introduce the disturbance observer (DOB) in the control system. Finally, we show that using our proposed DOB control method results in less interference in the 2-DOF manipulator than when using the proportional integral (PI) control method.
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