Path Following with Authority Sharing between Humans and Passive Robotic Walkers Equipped with Low-Cost Actuators

A promising way to offset the reduced mobility of a large number of older adults is using robotic systems providing physical and cognitive support for the navigation in large and crowded public spaces. In the paper, we study a possible solution for guidance based on the action of electromechanical brakes mounted on the rear wheels. The solution does not require sophisticated sensing devices and aims to share the control authority between the user and the robotic platform: the system kicks in with quick corrections only in presence of deviations from the path or of dangerous situations. The level of the shared authority is controlled by means of a simple parameter. The control paradigm is based on an all–or–nothing policy relying on very rough actuators. In our experimental validation, all the users have been proficient in the use of the device after a short learning time.