Stability and enhancement analysis of a modelled self-balancing verticalized mobility aid using optimal control techniques

This research comprises an analytical study of the Gyrolift, a new type of robotic wheelchair mobility aid adapted from the Segway self-balancing human transporter, and suggests additional contributions to its development. The Gyrolift is equipped with an agility module that uses a verticalization system designed to assist users to reach a standing position. The verticalization system aids users with reduced mobility but with adequate control of their upper limbs to stand up from a seated position inside the stability constraints of the transporter. It allows users to safely maintain the standing position while moving to interact with the environment and access objects at elevated levels. The contribution of this research resides in an analysis of the stability performance of the verticalized self-balancing transporter system, through model-based design and the utilization of optimal control techniques. The control strategies developed could improve future designs of this type of self-balancing transporter system in terms of stability and enhanced disturbance rejection, thereby providing overall and reliable robustness. The results indicate that an alteration to the self-balancing transporter by integrating a verticalization chair will degrade the Gyrolift’s stability margins. The results further reveal disturbances that may cause instability, and an enhanced actuating system to improve stability performance is thus proposed.