Pneumatic Shape-shifting Fingers to Reorient and Grasp
This work addresses a domain-specific problem in robotics manipulation by providing an incremental improvement for gripper adaptability in handling cylindrical objects.
The paper tackled the problem of enabling a simple parallel-jaw gripper to reorient and grasp cylindrical objects by developing pneumatic shape-shifting fingers that change geometry based on air pressure, achieving a smooth transition between wedge-shaped and V-shaped forms to pivot and secure objects, with experimental results demonstrating successful reorientation from horizontal to vertical poses.
We present pneumatic shape-shifting fingers to enable a simple parallel-jaw gripper for different manipulation modalities. By changing the finger geometry, the gripper effectively changes the contact type between the fingers and an object to facilitate distinct manipulation primitives. In this paper, we demonstrate the development and application of shape-shifting fingers to reorient and grasp cylindrical objects. The shape of the fingers changes based on the air pressure inside them and attains two distinct geometric forms at high and low pressure values. In our implementation, the finger shape switches between a wedge-shaped geometry and V-shaped geometry at high and low pressure, respectively. Using the wedge-shaped geometry, the fingers provide a point contact on a cylindrical object to pivot it to a vertical pose under the effect of gravity. By changing to V-shaped geometry, the fingers localize the object in the vertical pose and securely hold it. Experimental results show that the smooth transition between the two contact types allows a robot with a simple gripper to reorient a cylindrical object lying horizontally on a ground and to grasp it in a vertical pose.