Analysis and experimental evaluation of an object-level in-hand manipulation controller based on the virtual linkage model

Abstract

Robot grasping and in-hand manipulation are nowadays very active research fields. Their study has been carried out since many years ago. A very important topic is object-level impedance controllers. While many different articles have been published during the last two decades, it seems not clear that most of the newer methods have taken the advantage over some older ones. Main reasons are related to the problem of validating such approaches due both to the limited number of existing robotic hands and to the high limitations of the simulation technology. It is the aim of this work to review one of this powerful approaches, with some extensions, and demonstrate that they still represent a strong basis for developing robust and efficient state-of-the-art object-level grasp and in-hand manipulation controllers. A review on the concept of the Virtual Linkage null-space parametrization, and its application to the implementation of object-level manipulation controllers will be given. Furthermore, a validation using the Openrave simulator configured with the ODE physical dynamics engine has been performed. The DLR-Hand II has been used in these experiments.