Claudio Melchiorri

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Robotics research has made extensive use of techniques based on the Moore-Penrose inverse, or generalized-inverse, of matrices. Recently, it has been pointed out how non-invariant results may, in general, be obtained applying these techniques to some areas of robotics, namely hybrid control and inverse velocity kinematics. Unfortunately, the problems are(More)
In this paper, the problem of online estimation of the mechanical impedance during the contact of a robotic system with an unknown environment is considered. This problem is of great interest when controlling a robot in an unstructured and unknown environment, such as in telemanipulation tasks, since it can be easily shown that the exploitation of the(More)
The possibility of operating in remote environments by means of telecontrolled systems has always been considered of relevant interest in robotics. For this reason, in the literature a number of different control schemes has been proposed for telemanipulation systems, based on several criteria such as passivity, compliance, predictive or adaptive control,(More)
The first part of this paper describes the development of a humanoid robot hand based on an endoskeleton made of rigid links connected with elastic hinges, actuated by sheath routed tendons and covered by continuous compliant pulps. The project is called UB Hand 3 (University of Bologna Hand, 3rd version) and aims to reduce the mechanical complexity of(More)
The purpose of this paper is to show how the Timoshenko beam can be fruitfully approached within the framework of distributed port Hamiltonian systems (dpH systems) so that rather simple and elegant considerations can be drawn regarding both the modeling and control of this mechanical system. After the distributed port Hamiltonian (dpH) model of the beam is(More)
In this paper, we study the interconnection of two robots, which are modeled as port-controlled Hamiltonian systems through a transmission line with time delay. There will be no analysis of the time delay, but its presence justifies the use of scattering variables to preserve passivity. The contributions of the paper are twofold: first, a geometrical,(More)
Rendering stiff virtual objects remains a core challenge in the field of haptics. A study of this problem is presented, which relates the maximum achievable object stiffness to the elements of the control loop. In particular, we examine how the sampling rate and quantization of position measurements interact with the inertia, natural viscous, and Coulomb(More)