Modeling of a pneumatic actuator through long pneumatic lines for teleoperation purpose

This paper presents the modeling of a pneumatic system devoted to a teleoperation application. The study deals with the specific problem of the additional dynamics introduced by the air hose length when the servovalves are located far from the pneumatic cylinder. The physical modeling of each component of the system leads to either a set of nonlinear ordinary differential equations (ODEs) or a set of nonlinear partial differential equations (PDEs). We show that a classical expansion around a working point provides a model consisting of a finite set of ODEs. A second aspect of this work relates to the use of this model within a bilateral teleoperation scheme. In order to design a two-channel teleoperation controller, a model reduction is required. Simulation results show the efficiency of our approach in terms of both robustness with respect to modeling errors and transparency, whether in free space or in contact motion.