  In this study, a new concept of a wheelchair-towing robot for the facile
electrification of manual wheelchairs is introduced. The development of this
concept includes the design of towing robot hardware and an autonomous driving
algorithm to ensure the safe transportation of patients to their intended
destinations inside the hospital. We developed a novel docking mechanism to
facilitate easy docking and separation between the towing robot and the manual
wheelchair, which is connected to the front caster wheel of the manual
wheelchair. The towing robot has a mecanum wheel drive, enabling the robot to
move with a high degree of freedom in the standalone driving mode while
adhering to kinematic constraints in the docking mode. Our novel towing robot
features a camera sensor that can observe the ground ahead which allows the
robot to autonomously follow color-coded wayfinding lanes installed in hospital
corridors. This study introduces dedicated image processing techniques for
capturing the lanes and control algorithms for effectively tracing a path to
achieve autonomous path following. The autonomous towing performance of our
proposed platform was validated by a real-world experiment in which a hospital
environment with colored lanes was created.
