Application of nonlinear model predictive controller for fes-assisted standing up in paraplegia

Functional electrical stimulation (FES) is a method of restoring functional movements in patients of spinal cord injury that electrically induces muscle contractions. Nonlinear dynamics of paraplegics during standing up and limits of the physiological actuators suggest "Nonlinear Model Predictive Control" as a good candidate to follow desired trajectory and maintaining standing no need to learning or tuning many parameters such as many nonlinear controllers that had been used previously. In this work, the theoretical possibility of FES assisted standing up in paraplegic patient is studied using Nonlinear Model Predictive Control approach by computer simulation. The proposed controller shows good tracking behavior for ankle, knee and hip joint angles in simulated paraplegic standing up and improves patient safety because of considering constraints in control.