Humans and robots have need to work together in factories, in nuclear facilities, in space and in medicine. To make the interaction inherently safe, this research is investigating the concept of controlled passive robotic interface. The interface under study is essentially an arm with only dissipative (brakes or clutches) or conservative (transmissions) coupling between joints. No motors are used. Forces applied at the end of the arm result in motion that can be computer controlled according to the purposes of the device: to follow a prescribed path, to restrict access to some regions of the workspace, or to provide a haptic display representing the nature of a virtual or remote environment. Experiment and analysis will produce a model of the human-machine interaction. An experimental test bed developed under prior funding will be enhanced to support the current research. At the same time a much smaller scale device is planned with a focus on haptic displays, enabling wider exploration of the range of potential applications of the basic concept. Experiments will be conducted on the device and on its interaction with a human user. The information transmission capability and the trajectory enhancement capability are two related aspects to be studied experimentally and incorporated into the model of interaction. Theoretical studies will be conducted to predict the bounds on the performance to be expected with different controllers.
