Virtual Friction Display of Hybrid Force Feedback Interface with Actuators Comprising DC Motor and Magnetorheological Brake

This paper mainly deals with the stability of hybrid force feedback interface during displaying virtual Coulomb friction. The hybrid force feedback interface employs DC motor and magnetorheological (MR) brake as actuators. Firstly the paper theoretically presents how friction affects stability using the describing function method and the absolute stability theory. Secondly the paper provides experimental results for displaying virtual Coulomb friction to verify the theoretical analysis. The results showed that the hybrid force feedback interface realistically display the virtual Coulomb friction with guarantee of stability