Analysis of Control Architectures for Teleoperation Systems with Impedance/Admittance Master and Slave Manipulators

TLDR

Many bilateral teleoperation control architectures assume impedance models, yet hydraulic or heavily geared manipulators cannot be accurately described by such models. This paper extends a common four‑channel bilateral control architecture to accommodate both admittance and impedance master and slave manipulators, and investigates its stability and robustness to time delays and model uncertainties. The analysis employs the passivity‑based Llewellyn two‑port network absolute stability criterion and bounds on the transmitted impedance to the operator. Under ideal conditions, control parameters achieving perfect transparency are identified, and the evaluation results yield design guidelines for selecting appropriate architectures and parameters for different manipulator types.

Abstract

A large number of bilateral teleoperation control architectures in the literature have been designed based on assumed impedance models of the master and slave manipulators. However, hydraulic or heavily geared and many other manipulators cannot be properly described by impedance models. In this paper, a common four-channel bilateral control architecture designed for the above impedance models is extended to teleoperation systems with master and slave manipulators of either the admittance or impedance type. Furthermore, control parameters that provide perfect transparency under ideal conditions are found for each type of teleoperation system. Because in practice such parameters may not lead to systems that are robust to time delays and model uncertainties, an analysis of the stability and performance robustness of this very general architecture and two-channel architectures is also presented. The analysis uses the passivity-based Llewellyn two-port network absolute stability criterion, as well as bounds on the minimum and range of values of the impedance transmitted to the operator. The results of these evaluations provide design guidelines on choosing a particular control architecture and its parameters given different master and slave manipulator structures.