Manipulation Planning Using Environmental Contacts to Keep Objects Stable under External Forces

This paper addresses the problem of sequential manipulation planning to keep an object stable under changing external forces. Particularly, we focus on using object-environment contacts. We present a planning algorithm which can generate robot configurations and motions to intelligently use object-environment, as well as object-robot, contacts, to keep an object stable under forceful operations such as drilling and cutting. Given a sequence of external forces, the planner minimizes the number of different configurations used to keep the object stable. An important computational bottleneck in this algorithm is due to the static stability analysis of a large number of configurations. We propose a containment relationship between configurations, to prune the stability checking process.