Manipulation of Convex Objects via Two-agent Point-contact Push

Abstract

This paper explores a sensorless manipulation method for orienting and translating convex objects in the plane. The manipulation task is performed by a two-agent point-contact push. During the manipulation, each agent makes a point contact with the object, and both agents push together along a straight-line. One advantage of the two-agent point-contact push over the physical fence based push is that the two-agent point-contact push can manipulate non-polygonal parts, and reduce the position and orientation uncertainties simultaneously. First, two manipulation primitives are identified, equilibrium and non-equilibrium pushes, and the motion of the object characterized under these two pushing actions. Then, a controllability analysis is conducted for this class of manipulation using the theory of positive bases. After the analysis, the planning problem is studied in the framework of a switched system, and an analytical solution to the planning problem is developed. Finally, manipulation examples and experiments are provided to demonstrate the proposed manipulation method.