Robot Manipulation Planning Among Obstacles: Grasping, Placing and Rearranging

Time: Mon 2020-02-17 13.00

Location: F3, Lindstedtsvägen 26, Stockholm (English)

Subject area: Computer Science

Doctoral student: Joshua Alexander Haustein , Robotik, perception och lärande, RPL

Opponent: Associate Professor Kostas E. Bekris, Rutgers University, USA

Supervisor: Danica Kragic, Robotik, perception och lärande, RPL


This thesis presents planning algorithms for three different robot manipulation tasks: fingertip grasping, object placing and rearranging. Herein, we place special attention on addressing these tasks in the presence of obstacles. Obstacles are frequently encountered in human-centered environments and constrain a robot's motion and ability to manipulate objects. In narrow shelves, for example, even the common task of pick-and-place becomes challenging. A shelf is difficult to navigate and many potential grasps and placements are inaccessible. Hence, to solve such tasks, specialized manipulation planning algorithms are required that can cope with the presence of obstacles.

For fingertip grasping, we first present a framework to learn models that encode which grasps a given dexterous robot hand can reach. These models are then used to facilitate planning and optimization of fingertip grasps. Next, we address the presence of obstacles and integrate fingertip grasp and motion planning to generate grasps that are reachable by a robot in complex scenes.

For object placing, we first present an algorithm that plans the placement of a grasped object among obstacles so that a user-given placement objective is maximized. We then extend this algorithm, and incorporate planning in-hand manipulation to increase the set of placements a robot can reach.

Lastly, we go beyond pure collision avoidance and study object rearrangement planning. Specifically, we consider the special case of non-prehensile rearrangement, where a robot rearranges multiple objects through pushing. First, we present how a kinodynamic motion planning algorithm can be augmented with learned models to rearrange a few target objects among movable and static obstacles. We then present how we can use Monte Carlo tree search to solve a large-scale rearrangement problem, where a robot is tasked to spatially sort many objects according to a user-assigned class membership.