Optimal control for balance assistance using a robotic rollator

Research concerning intelligent robotic mobility aids for elderly people is raising in importance due to the prediction of the increase in the average age of the population in the near future and the consequent lack in professional care that can be expected. Such devices could provide not only navigational and cognitive assistance, but also enhanced physical support, for example when the patient is standing up or losing balance while walking or standing. This work considers a robotic rollator equipped with actuated handles which are capable of motions on the sagittal plane. The aim is to develop a methodology, based on optimal control and rigid body models of the user and of the device, to compute optimal handle trajectories to help the user regain an upright, balanced posture starting from perturbed initial conditions while standing without walking. Handle trajectories for different initial perturbations of the patient are computed for the MOBOT project rollator device and presented.