Evaluating the Linearized Feedback Controller for Regulation of Aided Sit-to-Stand in Subjects with Spinal Cord Injuries

Presented was an investigation on the performance of the feedback linearization control (FLC) method for the FES induced STS movement application in paraplegia. Improving the operation condition of the FES induced movement is one of the challenges currently receiving attention by so many scholars in the field. The Newton-Euler and Euler-Lagrange methods are utilised to check its correctness together with the muscle model proposed by Ferrarin and Pedotti. The FLC was evaluated for the system with and without fatigue disturbance. Although the fatigue disturbance was introduced in the system, results revealed that the cumulative current, cumulative rate of change in current the cumulative rate of change in current, RMSE, tracking error, cumulative tracking error and the level of the control signal, were by far better for the FL than that of the PID control technique with wide margins. Therefore, results portrayed that the FL control system the tendency to annul the effects of the effect of fatigue with higher capability over the gain scheduling based PID control method. It also indicates superiority in terms of system stability.