A Comparative Study on the Effectiveness of 2-DOF and 3-DOF Differential Drive Robotic Systems for Human Mobility Support

Wheelchairs, whether electric or manual, primarily serve to transport individuals, including those with disabilities or the elderly, from one place to another. Enhancing their quality of life has become a key societal challenge, driving the integration of robotic technologies into mobility solutions. Traditional robotic wheelchairs use a 2-DOF differential-drive platform, enabling linear motion and rotation but limited to transportation. This study explores expanding functionality by incorporating body movement control in electric wheelchairs. A 3-DOF mobility platform, Volting, introduces an additional movement, lateral tilt, enhancing mobility and adaptability. However, the comparative performance of 2-DOF and 3-DOF platforms remains unclear. To address this, an experimental study analyzed user experience during navigation and dancing tasks, chosen to represent conventional and exploratory movement. The study also included both visually normal and simulated visually impaired users (blindfolded participants). Results revealed distinct characteristics of each platform across different tasks and user groups, providing valuable insights for future robotic mobility design.