Experimental quantitative comparison of different control architectures for master-slave teleoperation

A procedure for experimental evaluation and objective/quantitative comparison among the different teleoperation architectures and systems is proposed. It is based on the analysis of the different matrices that can define the teleoperated system (two-port representations) and the selection of a set of four parameters that are easy to estimate via simple experimentation: free motion impedance, position tracking in free movement, force tracking in hard contact tasks and maximum transmittable impedance. These parameters provide complete characterization of the master-slave system and have clear physical interpretation. Furthermore, they require no maneouvering of the slave robot, which is very useful in the case of heavy or nonaccessible industrial robots. The method has been applied to compare position-position (PP), force-position (FP), and four-channel (4C) controllers in a 2 DOF master-slave system. Experimental measuring for all four parameters will be shown, proving the 4C architecture clearly better than any other.