The design of an underactuated wheelchair-mounted robotic arm to unlatch door knobs and handles

Wheelchair-mounted robot arms are typically designed with many degrees of freedom to provide users with a general-purpose device for manipulating many of the objects necessary for activities of daily living. However, commercially available systems are quite expensive and are usually not covered by insurance. An underactuated door-opening robotic arm (DORA) has been developed that has the potential to increase a power wheelchair user's accessibility to indoor spaces. DORA is designed specifically to unlatch door knobs and door handles while being permanently mounted to a power wheelchair. The gripper design requires only a single motor to turn various types of door knobs and handles, and a minimized arm configuration is used to keep the cost of the robot arm low. Although DORA is able to unlatch a number of door knobs and handles with similar characteristics, there are several limitations to the design that need to be addressed prior to using the robot in a rehabilitation environment.