Emmanuel Nuno

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In a recent scheme, with delayed derivative action [Lee and Spong, IEEE Trans. Robot., vol. 22, no. 2, pp. 269--281, Apr. 2006], it is claimed that a simple proportional derivative (PD) scheme yields a stable operation. Unfortunately, the stability proof hinges upon unverifiable assumptions on the human and contact environment operators, namely, that they(More)
In Chopra et al (2008) [Chopra, N., Spong, M. W., & Lozano, R. (2008). Synchronization of bilateral teleoperators with time-delay. Automatica, 44(8), 2142–2148], an adaptive controller for teleoperators with time-delays, which ensures synchronization of positions and velocities of the master and slave manipulators, and does not rely on the use of the(More)
This paper addresses the problem of stable bilateral teleoperation, through a time-delayed communication channel, for a n-DOF system without position drift. The classical wave variables-based scheme encodes velocity and force whilst the proposed scheme encodes position and integral of force. The resulting passive communication scheme is used in an extended(More)
This paper presents an adaptive controller for the bilateral teleoperation of a system composed by a single local manipulator and multiple cooperative remote manipulators handling a common object. First, the nonlinear operational space dynamical behavior of the complete teleoperation system is derived. Then, under the assumptions that the remote(More)
This paper aims to take a first step towards the unification of the stability analysis for teleoperators with time-delays. It proposes a general Lyapunov-like function that, upon slight modification, allows to analyze the stability of different control schemes, ranging from constant to variable time delays, with or without the scattering transformation and(More)