Full-Dynamics-Based Bilateral Teleoperation of Hydraulic Robotic Manipulators

Teleoperated robotic manipulators can augment human capabilities to remotely operate environments which are hard to reach or too dangerous for humans. Furthermore, in teleoperated tasks where heavy objects are manipulated or great forces are needed, a hydraulic slave manipulator may be the only suitable option. Motivated by the recent advances in nonlinear model-based (NMB) control of hydraulic robotic manipulators, this study proposes a full-dynamics-based bilateral force-reflected teleoperation, which is designed between a multiple degrees-of-freedom (n-DOF) electrical master manipulator and an n-DOF hydraulic slave manipulator. Based on the authors' knowledge, this is the first time that such a system is designed for the teleoperation of hydraulic manipulators. The individual controllers for the master and slave manipulators are designed based on the virtual decomposition control (VDC) approach. Furthermore, a communication channel is designed to couple the two manipulators. Very importantly, this allows arbitrary motion and force scaling between the master and slave manipulators. The performance of the proposed method is demonstrated with a full-scale two-DOF hydraulic slave manipulator.