Dynamic manipulation with a one joint robot

Abstract

We are interested in using low degree-of-freedom robots to perform complex manipulation tasks by not grasping. By not grasping, the robot can use rolling, slipping, and free flight to control more degrees-of-freedom of the part. To demonstrate this we study the controllability properties of planar dynamic nonprehensile manipulation. We show that almost any planar object is small-time locally controllable by point contact, and the controlling robot requires only two degrees-of-freedom (a point translating in the plane). We then focus on a one joint manipulator (with a two-dimensional state space) and show that even this simplest of robots, by using slipping and rolling, can control an object to a full-dimensional subset of its six-dimensional state space. We have developed a one joint robot to perform a variety of dynamic tasks, including snatching an object from a table, rolling an object on the surface of the arm, and throwing and catching.