Design, simulation and testing of a new modular wheelchair mounted robotic arm to perform activities of daily living

Abstract

A new and light wheelchair-mounted robotic arm (WMRA-II) was designed and built to meet the needs of mobility-impaired persons with limitations of upper extremities, and to exceed the capabilities of current devices of this type. The structure of the new robotic arm utilizes carbon-fiber and polycarbonate tubes to reduce the arm weight. The mechanical design incorporates DC servo drive, with actuator hardware at each individual joint, allowing reconfigurable link lengths. It has seven degrees of freedom and uses a side mount on a power wheelchair. A single control board that is capable of controlling eight motors was used for coordinated Cartesian control of the robotic arm. This paper discusses the current state of the art in WMRAs; describes the design goals and user requirements for this device; explains the component selection process; discusses details of the mechanical design and the controller design; and describes the testing of the completed arm. Further improvements are also suggested.