Tracking Control for FES Alternate Knee Bending and Stretching Trike With Electric Motor Assistance

This paper deals with a new control method for functional electrical stimulation ( FES) alternate knee bending and stretching trike with electric motor assistance. While FES-cycling is known as a beneficial exercise for people with movement disorders, a paraplegia patient could not pedal smoothly by applying the previous method. One of the possible reasons is that there is a dead point in the pedaling motion intrinsically. To overcome this drawback, we developed a trike system which can be moved by alternating knee bending and stretching of the left and right legs for paraplegia patients. Electric motor assistance plays an important role to recover deceleration of the trike when switching between flexion and extension. Stability of the developed control law is analyzed through Lyapunov-based methods.