A Constraint-Aware Motion Planning Algorithm for Robotic Folding of Clothes

Motion planning for robotic manipulation of clothing is a challenging problem as clothing articles have high-dimensional configuration spaces and are computationally expensive to simulate. We present an algorithm for robotic cloth folding that, given a sequence of desired folds, outputs a motion plan consisting of a sequence of primitives for a robot to fold the cloth. Previous work on cloth folding does not take into account the constraints of the robot, and thus produces plans which are often infeasible given the kinematics of robots like the Willow Garage PR2. In this paper we introduce a class of motion primitives that start and end in a subset of the cloth’s state space. To find a sequence of primitives that achieves all required folds, the algorithm takes advantage of the partial ordering inherent in folding, and produces a time-optimal motion plan (given the set of primitives) for the robot if one exists. We describe experiments with a general purpose mobile robotic platform, the PR2, folding articles that require dragging and base motion in addition to folding. Our experiments show that (1) many articles of clothing conform well enough to the assumptions made in our model and (2) this approach allows our robot to perform a wide variety of folds on articles of various sizes and shapes.