Numerical Simulator for Manual Wheelchair Propulsion based on a MPC Approach

Abstract

Quite recently, considerable attention has been paid to the concept of prediction of manual wheelchair locomotion by a predictive model simulation, with the aim of facilitating the synthesis of the biomechanics of propulsion movement and improving the wheelchair ergonomics. Generally, the biomechanical modeling of wheelchair propulsion is a highly nonlinear that depends on the upper limb motion and the contact force between the human hand and the handrim, which will increase the complexity of implementing these models to evaluate with numerical simulation the biomechanics of propulsion. In this context, a new approach for the propulsion motion prediction of a manual wheelchair based on nonlinear model predictive control (NMPC) has been proposed. Based only on the kinematics of the hand on the handrim and the dynamics of the rear wheels, this approach is able to predict the optimal hand contact on the handrim, during the push phase and the optimal hand trajectory during the recovery phase. Thus, for a given speed configuration, the predictive model simulation is able to generate the most suitable propulsion scheme. The advantage of using a simple model of the hand-wheel interaction, could allow for an easier implementation while providing a fully predictive simulation of the wheelchair propulsion. Simulation results are presented, showing the effectiveness of the proposed approach.