  In this work, we present a manipulation planning algorithm for a robot to
keep an object stable under changing external forces. We particularly focus on
the case where a human may be applying forceful operations, e.g. cutting or
drilling, on an object that the robot is holding. The planner produces an
efficient plan by intelligently deciding when the robot should change its grasp
on the object as the human applies the forces. The planner also tries to choose
subsequent grasps such that they will minimize the number of regrasps that will
be required in the long-term. Furthermore, as it switches from one grasp to the
other, the planner solves the problem of bimanual regrasp planning, where the
object is not placed on a support surface, but instead it is held by a single
gripper until the second gripper moves to a new position on the object. This
requires the planner to also reason about the stability of the object under
gravity.We provide an implementation on a bimanual robot and present
experiments to show the performance of our planner.
