Dexterous Ungrasping Manipulation in Three Dimensions

Abstract

This study focuses on the robotic capability of ungrasping, or releasing, an object in a grasp from the gripper to the robot's environment. The presented technique enables the delicate release of a grasped object using non-static contacts, allowing for rolling and/or sliding. This dexterous manipulation capability is particularly relevant when ungrasping thin or slender objects, as will be demonstrated with real examples. We initially discuss the establishment of three-dimensional stability during ungrasping manipulation, ensuring robustness. Subsequently, we present a planning and control solution for three-dimensional ungrasping, building upon our previous planar version. A series of experiments across various test scenarios, ranging from precision placement to puzzle tiling, showcase the viability and effectiveness of our approach.