1 IMECE2010-40606 ABSTRACT In this paper a new stable adaptive control for a Macro- Micro bilateral teleoperation system is proposed. Our platform to implement the controllers consists of a servo DC motor (macro) as the master robot and a piezo-actuator (micro) as the slave robot. Piezo-actuator has some characteristics which disturb the transparency and stability of the teleoperation system. We add a nonlinear disturbance observer to the slave robot controller in order to observe and compensate the disturbances. It is recognized that the presence of time delay is one of the largest barriers in teleoperation systems. This problem is mainly due to the distance separating the master from the slave and also is due to lag effect of filters and motor drivers. Because the time delay is unknown and variable, it can make the system unstable. In this paper, all of the above controllers are discussed using variable time delay. The stability of the system under variable time delay is guaranteed by Lyapunov stability criterion and passivity based methods. Tracking of force/position is achieved by selecting the best design parameters. Performance of the proposed control is validated by experimental results. Keywords: Macro/Micro Teleoperation, variable Time Delay, Adaptive control. INTRODUCTION Bilateral teleoperation systems are composed of two sides namely master and slave. The aim of such an arrangement is that the position command dictated by master side is followed by the slave side and simultaneously the force measurement of the remote environment experienced by slave is transferred to the mater - human operator. Teleoperation systems are mainly used where the slave side is hazardous and unknown for human. So using a controller which can determine the slave robot and its environment characteristics is inevitable. Because of the unknown environment and system uncertainties, several robust control systems have been reported [1, 2 and 3]. The robots in the teleoperation systems are coupled to each other by a communication network. This communication channels exert a time delay to the transferred data from master robot to slave robot and vice versa. Time delay is one the important factors that can disturb the system and make it unstable. Also by living in a borderless world, using internet network as the communication channel is inevitable. But in this type of network, the time delay is variable due to change in bandwidth and distance. This variable time Adaptive control of a Macro/Micro Bilateral Teleoperation System under variable Time Delay A. Monemian Esfahani S.M. Rezaei Department of Mechanical Engineering Amirkabir University of Technology, Tehran, Iran. a.monemian@aut.ac.ir Department of Mechanical Engineering Amirkabir University of Technology, Tehran, Iran. smrezaei@aut.ac.ir M. Zareinejad Mozafar Saadat Department of Mechanical Engineering Amirkabir University of Technology, Tehran, Iran. mzare@aut.ac.ir Mechanical Engineering The University of Birmingham M.Saadat@bham.ac.uk Proceedings of the ASME 2010 International Mechanical Engineering Congress & Exposition IMECE2010 November 12-18, 2010, Vancouver, British Columbia, Canada IMECE2010- Copyright © 2010 by ASME Downloaded From: http://proceedings.asmedigitalcollection.asme.org/ on 05/19/2013 Terms of Use: http://asme.org/terms