Soft Hand Kinematics | Sumit Patidar

About

The RBO hand 3 is a soft robotic hand developed at Robotics and Biology Laboratory (RBO) at Technical University of Berlin. It is a highly compliant hand designed for dexterous grasping. The inherent compliance of the fingers makes it hard to model them analytically unlike their rigid links counterparts. Therefore, in this project, we investigate efficient data-driven approach to learn the forward and inverse kinematic models of the hand to control and visualize the hand in free space.

We used a small feed-forward network to model the pose of fingertips as a function of airmass. In addition, palm and T{1-3} bellow actuators are modeled as revolut joints. The ring and little finger, and thumb form a chain of connected joints with their respective bellows. The final finger pose is computed by taking into account airmass in each finger compartments along with palm and thumb bellows (T1,T2,T3).

The RBO Hand 3. Each finger has two pressure chambers except thumb which has one chamber.

Reachable workspace of the finger tips (without palm bellow and T1, T2, T3 bellow actuation)

Reachable workspace of the little and ring finger with palm actuation

Reachable workspace of the thumb with T1, T2 and T3 bellow actuations

Team

Sumit Patidar, Adrian Sieler (Mentor)

References

[1] Puhlmann, S., Harris, J. and Brock, O., 2022. RBO hand 3: A platform for soft dexterous manipulation. IEEE Transactions on Robotics, 38(6), pp.3434-3449.

[2] Bhatt, A., Sieler, A., Puhlmann, S. and Brock, O., 2022. Surprisingly robust in-hand manipulation: An empirical study. arXiv preprint arXiv:2201.11503.