A real time human grasp simulation with deformable fingertips
MS'06 Proceedings of the 17th IASTED international conference on Modelling and simulation
A geometric approach to automated fixture layout design
Computer-Aided Design
On the Passive Force Closure Set of Planar Grasps and Fixtures
International Journal of Robotics Research
Grasping of deformable objects applied to organic produce
TAROS'11 Proceedings of the 12th Annual conference on Towards autonomous robotic systems
Soft robotics: Biological inspiration, state of the art, and future research
Applied Bionics and Biomechanics
| Hi-index | 0.00 |
Because friction is central to robotic grasp, developing an accurate and tractable model of contact compliance, particularly in the tangential direction, and predicting the passive force closure are crucial to robotic grasping and contact analysis. This paper analyzes the existence of the uncontrollable grasping forces (i.e., passive contact forces) in enveloping grasp or fixturing, and formulates a physical model of compliant enveloping grasp. First, we develop a locally elastic contact model to describe the nonlinear coupling between the contact force with friction and elastic deformation at the individual contact. Further, a set of “compatibility” equations is given so that the elastic deformations among all contacts in the grasping system result in a consistent set of displacements of the object. Then, combining the force equilibrium, the locally elastic contact model, and the “compatibility” conditions, we formulate the natural compliant model of the enveloping grasp system where the passive compliance in joints of fingers is considered, and investigate the stability of the compliant grasp system. The crux of judging passive force closure is to predict the passive contact forces in the grasping system, which is formulated into a nonlinear least square in this paper. Using the globally convergent Levenberg-Marquardt method, we predict contact forces and estimate the passive force closure in the enveloping grasps. Finally, a numerical example is given to verify the proposed compliant enveloping grasp model and the prediction method of passive force closure. © 2005 Wiley Periodicals, Inc.