Pressure Feedback Control Based on Singular Perturbation Method of an Electro-Hydrostatic Actuator for an Exoskeletal Power-Assist System

摘要

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 electro-hydrostatic actuator with estimated torque feedback. The controllers were implemented on an exoskeletal power-assist system for a knee joint with an electro-hydrostatic actuator. Their efficacy was evaluated by experiments.