Authors:
Dimitar Chakarov
;
Ivanka Veneva
and
Pavel Venev
Affiliation:
Institute of Mechanics, Bulgarian Academy of Sciences, “Acad. G. Bonchev” str., Block 4, Sofia 1113, Bulgaria
Keyword(s):
Exoskeleton, Pneumatic Drive, Positive Pressure, Vacuum Pressure, Simulations, Harmonic Motion, Interaction Force, Safety, Transparency.
Abstract:
In the present work, an exoskeleton of upper limb intended for rehabilitation and training is studied. The aim of the work is to find and evaluate an appropriate design solution that provides performance on the one hand and transparency and natural safety on the other. Therefore, a pneumatic drive is proposed and transparency of the exoskeleton is investigated, where positive pressure actuation is compared with vacuum pressure actuation. To assess transparency, the interaction force between the patient and the exoskeleton in passive mode is examined. Simulations and estimates of the interaction force between the patient and the exoskeleton as a result of exoskeleton gravity and the elastic forces from the pneumatic actuation are performed. In this case, the forces in the closed chambers of the pneumatic actuators are used to compensate for the gravitational forces. Simulations are performed with harmonic motion imposed by the patient at one joint of the exoskeleton. The interaction f
orce at the end effector is evaluated in two cases of pneumatic actuation: at pressures higher than atmospheric pressure and at vacuum pressure. The simulation results are shown graphically. A discussion is presented as well as conclusions and directions for future work.
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