A general framework for open-loop pivoting

Pivoting is the rotation of an object between two fingers using gravity and inertial forces to impart angular momentum. We present an analysis of the mechanics of pivoting and a framework for planning and execution. Extrinsic dexterity was defined by Chavan-Dafle et al. [1] as the use of external forces, such as gravity and inertial forces in post grasp manipulation. We analyze one such regrasp termed “pivoting” by Rao et al. [2]. We find a grasp and arm trajectory which can rotate an object between stable poses, if any. We demonstrate an implementation of pivoting with an ABB industrial arm and a two fingered gripper.

Authors

• Anne Holladay
• Robert Paolini
• Matthew T. Mason

Keywords

• Trajectory
• Grippers
• Face
• Gravity
• Dynamics
• Manipulator dynamics
• Angular Momentum
• Object Rotation
• Collision
• Center Of Mass
• Flat Surface
• Workspace
• Rotation Axis
• Convex Hull
• Direction Of Rotation
• Object Motion
• Direct Line
• End-effector
• Unit Sphere
• Moment Arm
• Object Pose
• Robotics Research
• Triangular Prism
• Capture Region