An impedance grasping strategy

This work is devoted to an impedance grasping strategy for a class of standard mechanical systems in the port-Hamiltonian framework. The presented control strategy requires a set of coordinate transformations, since the impedance control in the port-Hamiltonian framework with structure preservation is not straightforward. The impedance grasping control is achieved via a virtual spring with a variable rest length. The force that is exerted by the virtual spring leads to a dissipation term in the impedance grasping controller which is needed to obtain a smoother noncontact to contact transition. Simulations results are given in order to motivate our results.