Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Optimal Control Simulations of Two-Finger Precision Grasps

: Phutane, U.; Roller, M.; Björkenstam, S.; Leyendecker, S.


Kecskeméthy, A.:
Multibody Dynamics 2019 : Proceedings of the 9th ECCOMAS Thematic Conference on Multibody Dynamics, 15-18 July 2019, Duisburg, Germany
Cham: Springer International Publishing, 2020 (Computational methods in applied sciences 53)
ISBN: 978-3-030-23131-6 (Print)
ISBN: 978-3-030-23132-3 (Online)
Thematic Conference on Multibody Dynamics <9, 2019, Duisburg>
Fraunhofer ITWM ()
Fraunhofer FCC ()

Grasping is a complex human activity performed with readiness through a complicated mechanical system as an end effector, i.e. the human hand. Here, we apply a direct transcription method of discrete mechanics and optimal control with constraints (DMOCC) to reproduce human-level grasping of an object with a three-dimensional model of the hand, actuated through joint control torques. The equations of motions describing the hand dynamics are derived from a discrete variational principle based on a discrete action functional, which gives the time integrator structure-preserving properties. The grasping action is achieved through a series of constraints, which generate a hybrid dynamical system with a given switching sequence and unknown switching times. To determine a favourable trajectory for grasping action, we solve an optimal control problem (ocp) with an objective involving either the contact polygon centroid or the control torques subject to discrete Euler-Lagrange equations, boundary conditions and path constraints.