Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Active Knee Orthosis Adaptive Impedance Control Based on the Human Impedance Determined by Polynomial Method
Submission Author:
Denis César Mosconi Pereira , SP
Co-Authors:
Denis César Mosconi Pereira, Adriano Siqueira
Presenter: Denis César Mosconi Pereira
doi://10.26678/ABCM.COBEM2021.COB2021-0050
Abstract
The development of interaction controls is of extreme importance for the field of robot assisted therapy. Such controls must meet the safety and efficacy requirements relevant to the treatment, in order to guarantee the good and safe recovery of the patient. The purpose of this work is to present and simulate an active knee orthosis adaptive impedance control whose adaptation law is based on the human knee impedance and whose purpose is to help the patient to perform the rehabilitation exercises, providing an auxiliary torque in order to ensure the maintenance of the amplitude and pattern of movement. To determine the human knee impedance, we also propose a novel polynomial method, seeking to introduce a tool that is able to determine human impedance directly from EMG signals, without the need of to estimate the human torque which could to introduce uncertainties and to increase the computational cost. The simulations will be performed utilizing a human-orthosis interaction model consisting of a neuromusculoskeletal model provided by OpenSim in whose knee articulation a coordinate actuator was added in order to computationally emulate the active knee orthosis and that was validated in previous works. Experimental data of angular position and EMG signals from a user performing sinusoidal movements of extension and flexion of the knee are used. We will compare the human impedance obtained from the polynomial method with the one obtained from another different method. The results obtained with the adaptive impedance control will be compared with the ones obtained with a non-adaptive impedance control. At the end of this work, it is expected to have an effective polynomial method to determine the impedance of the human knee joint based on EMG, as well as an adaptive impedance control that takes into account not only the kinematics of the movement but also the biomechanical characteristics of the patient, being able to help him to perform the desired movements well, ensuring maintenance of the range and pattern of movement and attending to assist-as-needed protocol.
Keywords
Robotic Neurorehabilitation, OpenSim, Interaction control
