Previdi F., M. Ferrarin, S.M. Savaresi, S. Bittanti
This work is focused on the design of closed-loop controllers for FES-supported standing up and sitting down. This task is a
difficult one, due to the lack of stability of the considered system and to its nonlinear dynamic behaviour. In this paper, a control
strategy based on two nested control loops is presented. The inner loop is based on a linear PID controller that stabilizes the system.
The outer loop is designed using the Virtual Reference Feedback Tuning (VRFT) strategy, that allows a fast and easy tuning of the
controller starting from a single I/O data set. Both linear and nonlinear control laws are implemented exploiting the VRFT
algorithms. Simulation results showthat the proposed technique is effective in controlling a paraplegic patient in FES-based
standing up and sitting down.