Simulation of Control System of Executive Links of Rehabilitation Exoskeleton Considering Spasticity Effect

Abstract

Purpose of research. Mathematical modeling of the adaptive control system of the rehabilitation exoskeleton complex, which allows considering the effects of human interaction with the actuators of the drive system, including detecting the appearance of the spasticity effect. The authors of this work solve the following problems: development of human-machine interaction concept, description of the information infrastructure of the exoskeleton complex; development of a structure of an adaptive control system that allows to take into account the interaction of a person with a robot in the process of movement; development of a mathematical model of a man-machine system (MMS) and setting up computational experiments in order to develop adaptive control algorithms under various conditions, development of a method for detecting a spasticity phenomenon and an algorithm of an adaptive control system providing patient safety.Methods. When constructing a mathematical model of the MMS, biomechanical and physiological properties of the manipulation object, mechanical properties of power elements of the structure, as well as features of the operation of the information system of electromechanical device are considered. The work uses mathematical model represented by a system of differential equations of the second order, describing the dynamics of the joint movement of executive links of the exoskeleton and the limb of the operator.Results. During numerical simulation time diagrams of rotation angles changes of exoskeleton links and operator's leg, laws of torques changes in hinges and forces on cuffs characterizing man-machine interaction under various modes and conditions of device functioning are obtained.Conclusion. Conclusions were drawn on applicability of the proposed algorithms of adaptive control system under various modes and conditions of exoskeleton complex functioning, including for rehabilitation of patients with the possibility of spasticity. The conclusions were drawn based on the obtained results of mathematical modeling of MMS functioning.