Teleoperation by Using Nonisomorphic Mechanisms in the Master–Slave Configuration for Speed Control

This paper presents modeling, simulation, and control of a novel teleoperated mechanism, where two nonisomorphic manipulators are used in one integrated system, with the purpose of usage in oil and gas industry in the future. Overall integration of the teleoperated system has been done in the master–slave configuration, where a stuart-type 6-DOF parallel manipulator is used as a master robot and a 6-DOF serial manipulator is used as a slave robot. Since the parallel manipulator has a closed-loop structure and serial manipulator is an open-loop structure, their work spaces are of completely different nature in terms of overall shape and size. A novel task-space mapping mechanism has been proposed in this work to integrate these two completely nonidentical manipulators. Damped least-squares (DLS) method is used for overcoming the singularity of proposed task-space mapping matrix. This paper also presents detailed dynamic modeling of the parallel manipulator along with comprehensive analysis of proposed novel control technique. The biggest benefit of using proposed integration mechanism is the fullest access of the complete cartesian task spaces of both the master and slave manipulators. This paper also proposes usage of lag compensator for the improved tracking performance. Multilevel control architecture with local actuator-space and joint-space controllers, for the parallel and serial manipulators, respectively, has also been presented in this work.