PROJECT TITLE :

Isometric Torque Control for Neuromuscular Electrical Stimulation With Time-Varying Input Delay

ABSTRACT:

Previous results have shown experimental evidence that the muscle response to neuromuscular electrical stimulation (NMES) is delayed; the time lag is usually known as electromechanical delay. NMES closed-loop control strategies are developed to atone for a known constant input delay. But, as a muscle fatigues, this delay will increase. This paper develops a feedback controller that robustly compensates for the time-varying delay of an uncertain muscle model during isometric contractions. The controller is proven to yield international uniformly ultimately bounded torque tracking error. Experimental results illustrate the effectiveness of the developed controller and also the time-varying nature of the delayed response.