A multi-level fuzzy logic system for controlling the tibialis anterior FES envelop

Abstract

In this paper, a predictive two-level hierarchical fuzzy model is applied to control the FES envelop of disabled tibialis anterior (TA) muscle in patients with unilateral drop foot. The proposed control methodology is based on EMG signal of Rectus Femoris (RF) muscle of ipsilateral leg. Its control structure consists of an upper level fuzzy controller and a lower level direct fuzzy controller. The appropriate fuzzy if-then rules of lower level fuzzy logic system are extracted to model the existing muscle coordination profile between activities of ankle dorsiflexor muscle and ipsilateral knee extensor muscle of unimpaired side. Then the adjusted fuzzy logic system forecasted the TA muscle activity of one foot using rectus femoris muscle activity of ipsialateral foot during the overground walking. The results show quite promising and impressive performance of presented control scheme.