Transparency Improved Sliding-mode Control Design for Bilateral Teleoperation Systems by Using Virtual Manipulator Concept

This paper proposes a new methodology for designing sliding mode bilateral controllers based virtual manipulator concept that aims to reach the most transparency considering parameter uncertainties and disturbances. This method shows a modified scheme of the sliding mode control that leads the alleviation of the tradeoff between position and force tracking, which is crucial in certain teleoperation applications. An analysis of stability and transparency of the closed-loop teleoperation system is carried out. In addition, a new fuzzy logic scheme is also proposed to eliminate the chattering phenomena caused by sign function in the sliding mode controller. Simulation results show the superior performance of the proposed fuzzy sliding mode scheme, with respect to previous method, particularly in term of significantly ameliorating transparency in the presence of unknown parameters and disturbances.