Modeling and Control of Ankle Exoskeleton

This article presents the development of an exoskeleton designed to assist ankle flexion and extension in patients with reduced mobility, such as those with foot drop. The device is oriented towards passive rehabilitation exercises, for which a dynamic model of the exoskeleton is obtained using position and angular velocity sensors, considering the natural biomechanics of the limb and the degrees of freedom associated with its physiology. The implementation of a Proportional Derivative (PD) control with an additional term allows the ankle movement to be controlled precisely. Likewise, an inertial sensor is integrated that classifies the phases of gait by measuring the inclination of the foot with respect to the ground, generating precise commands to control the ankle movement. The simulation results suggest that the exoskeleton has a high potential to improve assistance processes, correctly following the defined trajectories and adapting to the different phases of movement, which facilitates a more efficient recovery in patients.