Delay Time Fractional-Order Model for the Soft Exoskeleton Glove Control

The biomechanical system of the soft exoskeleton glove is studied in this letter. In this context, several aspects have been treated. The delay time model with fractional-order exponent
${\boldsymbol{\beta }} = 1.5$
for a soft exoskeleton of a patient that suffered a cerebrovascular accident is proposed. The model contains two major elements of uncertainty: the first element is represented by the time delay that corresponds to the reaction time of the human factor and the second element is given by the disturbing muscular torque of the patient's hand. A robust control system is studied to ensure the desired performances of the tracking error relative to a reference position. The stability of the control system is demonstrated by the Lyapunov techniques. The control method and the resulting algorithms are implemented in the research stage of the soft EXOSKELETON-GLOVE (EX-GLOVE) model. The numerical simulations and experimental tests demonstrated the correctness of the proposed solutions.