Pressure Feedback Control Based on Singular Perturbation Method of an Electro-Hydrostatic Actuator for an Exoskeletal Power-Assist System
Hirokazu Tanaka, Hiroshi Kaminaga, and Yoshihiko Nakamura
Department of Mechano-Informatics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
This paper describes control methods of an Electro-Hydrostatic Actuators (EHA) for an exoskeletal power-assist systems. By increasing backdrivability of the electro-hydrostatic actuators, the exoskeletal power-assist systems can achieve haptic interaction with a human. We propose a pressure feedback controller based on singular perturbation method, which is used in a power-assist controller of the exoskeletal power-assist system. The controller assists human movements by increasing the sensitivity of the electrohydrostatic actuator with estimated torque feedback. The controllers were implemented on an exoskeletal power-assist system for a knee joint with an electrohydrostatic actuator. Their efficacy was evaluated by experiments.
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