Modeling Induced Master Motion in Force-Reflecting Teleoperation

Abstract

Providing the user with high-fidelity force feedback has persistently challenged the field of telerobotics. Interaction forces measured at the remote site and displayed to the user cause unintended master device motion. This movement is interpreted as a command for the slave robot and can drive the closed-loop system unstable. This paper builds on a recently proposed approach for achieving stable, high-gain force reflection via cancellation of the master mech anism’s induced motion. Such a strategy hinges on obtaining a good model of the master’s response to force feedback. Herein, we present a thorough modeling approach based on successive isolation of system components, demonstrated on a one-degree-of-freedom testbed. A sixth-order mechanical model, including viscous and Coulomb friction as well as a new method for modeling hysteretic stiffness, describes the testbed’s high-frequency resonant modes. This modeling method’s ability to predict induced master motion should lead to significant improvements in force-reflecting teleoperation via the cancellation approach.