Post-Contact, In-Hand Object Motion Compensation With Adaptive Hands

In this paper, we present a methodology based on constrained optimization methods for estimating and compensating for post-contact parasitic object motions for underactuated, compliant robot hands and for deriving stable, minimal effort grasps to try to minimize these movements. To do so, we compute the object motions for different hand designs, object shapes, and object sizes and we synthesize appropriate robot arm trajectories that eliminate them, even in hands with complex flexure-based compliant members. The effectiveness of the proposed methods is validated using a seven DOF robot arm (Barrett WAM) and a range of compliant underactuated robot hands (Yale OpenHand models T42PP, T42PF, and T42FF).