α-Variable adaptive model free control of iReHave upper-limb exoskeleton

Abstract

In order to provide the rehabilitation training for patients with impaired upper limb motor function, this article proposes an α-variable adaptive model free control (α-AMFC) for a 7-DOF upper limb exoskeleton which is denoted as iReHave and designed based on SolidWorks. The referred α-AMFC is developed based on a time-delay estimation based intelligent PID control (TDE-iPID) and an α online adaptive estimation law. The latter is integrated to enhance the performance of the TDE-iPID which is based on an ultra-local model, time-delay estimation and PID controller. Finally, to demonstrate the performance of the proposed α-AMFC on the iReHave 7-DOF upper limb exoskeleton, co-simulation results with comparisons to PID and TDE-iPID controller are given.