Passive bilateral teleoperation with constant time delays

Abstract

We propose a novel control framework for bilateral teleoperation of a pair of multi-degree-of-freedom (DOF) nonlinear robotic systems under constant communication delays. The proposed framework utilizes the simple proportional-derivative (PD) control, i.e. the master and slave robots are directly connected via spring and damper over the delayed communication channels. Using the controller passivity concept, the Lyapunov-Krasovskii technique, and Parseval's identity, we can passify the combination of the delayed communication and control blocks altogether robustly, as long as the delays are finite constants and an upper-bound for the round-trip delay is known. Having explicit position feedback through the delayed P-action, the proposed framework enforces master-slave position coordination which is often compromised in the velocity-based schemes (e.g. conventional scattering-based teleoperation). The proposed control framework provides humans with extended physiological proprioception so that s/he can affect and sense the remote slave environments mainly relying on her/his musculoskeletal systems. Experiments are performed to validate the proposed control framework