Abstract
Power assist robots need to estimate human motion to extend human physical abilities appropriately. In this paper, a control method for a knee power assist device using Electro-Hydrostatic Actuator(EHA) is proposed by using the fact that EHA is a singular perturbation system. The controller is based on singular perturbation control and uses disturbance observer to estimate external torque applied by operator. The estimated torque is used to increase sensitivity of the system by feedback control. The efficacy of the proposed method is evaluated by measured iEMG.
