A CONTROLLER FOR SIMULATING FREEDOM OF MOTION FOR A COBOT

Abstract: A method is presented for creating a controller to simulate free motion for a cobot. A cobot is a class of mechanically passive robotic devices, intended for direct physical collaboration with a human operator (Colgate, et al., 1996a). One common cobot application involves a person using the cobot’s endpoint to probe a virtual surface. This task requires that the user have freedom of motion while not in contact with the virtual surface. Because a cobot has only one degree of freedom at any given time, free motion must be simulated by re-directing this one-degree of freedom to coincide with the user’s desired motion direction. A technique for creating the free motion controller for a cobot is developed and simulated on a three revolute arm-like cobot. 1